305 to 350

[Irocz28chic]

I have a 305 but the rear main seal is leaking. I have a 350 four bolt main sitting in the garage. What is transferable from the 305 to the 350? The 305 had some mods done like roller cam,intake, etc. ( some retard took the TPI off and slapped a carb on though) I am not looking for major performance as I just wanna get it running for now. I miss it a lot. :( Next year I plan to buy a crate motor, the Z needs a clutch and cam installed this year. ;)

[MonteC]

everything that your trying to transfer over will transfer over. just unbolt and then rebolt it to the 350.

[Irocz28chic]

Is the bore the same on the pistons? If not, any recomendations? I know this seems crazy, but like I said, I just want it running for now. I drive my husbands Z everyday and he wants to drive my IROC to work as a daily driver. (I know sounds crazy) I think I have the better end of the deal. ;)

[MonteC]

no the bore is not the same. the bore on a 305 is 3.74" the bore on a 350 is 4". so no u cannot use the pistons from the 305 in the 350.

everything else will work.


what exactly are u planning on doing? i might be able to help a little more if i knew more details about what u are planning on doing.

[nightrider]

Roller cam in a 86 305? I assume that's just a mix match of terminology since it would be mostly a complete waste to dump 600 dollars into the cam of anotherwise stock non-roller motor.

what's left on the 350, or is it just a block? and what is on the 305?
all external parts will swap over.

pistons do not interchange...for what pistons cost for sbc's, even thinking of reusing any of them in a fresh rebuild is ridiculous.

[nightrider]

silly monte carlo man, posting in front of me.

It probably bother's mcdamit that i wont reply to the post he went out of his way to pm everyone about.

I also speculate that the other post with WRX guy is actually mcdamit posting under another name so that someone will answer his questions.

PS: captain south carolina would you do me a huge favor???? see post i'm about to type in the lounge.

[Irocz28chic]

Ok here is the deal with the car. I bought it from a guy who was selling it for his nephew. His nephew was a spoiled little brat who's daddy was a president of a bank. The kid apparently did some major redneck things with the car. First of all the car is an 86 but the block is an 87. I noticed the center bolt heads, so when I was rebuilding it I got the casting numbers. The car is an original TPI car....don't even wanna know why it is now carbed. Not sure on the deal with the cam....just happened to find that out after tearing the motor down. I have dumped a lot of money into this car and just don't wanna bother with the 305. But I also don't wanna get into a major build on the 350 since I'm just gonna by a crate motor early next year. I just want to throw the 350 in it and run with it basically. I've got paint for it sitting in the garage(since the redneck kid painted it black right over top of the beautiful blue it was originally) and I also have a rearend from an 01 Z waiting to be put on(gonna lose the IROC wheels though) The car has a long way to go, but I wanna have it running good enough to get it from point A to point B to have some of the other things done to it. Am I confusing anyone yet??

[Mcdamit]

No not really the question is does the 350 have pistons, if you dont have a crank or connecting rods those can be taken from the 305. The heads on the 305 (unless the redneck kid did something) should be standard 58cc 1.84 intake 1.5 exhaust heads. And should bolt right up to the 350 assuming it is of the correct years in the first gen engine family. Though if you have heads for the 350 it is advisable to stay with them if possible, unless the 305 heads have been heavily modified. If the year of the 5.7L block is not of the correct year, the cam or the block will need to be modified.

[MonteC]

Originally posted by Irocz28chic
Ok here is the deal with the car. I bought it from a guy who was selling it for his nephew. His nephew was a spoiled little brat who's daddy was a president of a bank. The kid apparently did some major redneck things with the car. First of all the car is an 86 but the block is an 87. I noticed the center bolt heads, so when I was rebuilding it I got the casting numbers. The car is an original TPI car....don't even wanna know why it is now carbed. Not sure on the deal with the cam....just happened to find that out after tearing the motor down. I have dumped a lot of money into this car and just don't wanna bother with the 305. But I also don't wanna get into a major build on the 350 since I'm just gonna by a crate motor early next year. I just want to throw the 350 in it and run with it basically. I've got paint for it sitting in the garage(since the redneck kid painted it black right over top of the beautiful blue it was originally) and I also have a rearend from an 01 Z waiting to be put on(gonna lose the IROC wheels though) The car has a long way to go, but I wanna have it running good enough to get it from point A to point B to have some of the other things done to it. Am I confusing anyone yet??

ok first off if u want good advice dont listen to that kid with the screen name mcdamit ok? he knows very little about cars and tries to give tech adviced by parroting what someone else has already typed.

stick with nightriders or my advice and u should be good as gold.


ok u just wann drop this 350 in there, well im assuming its already got heads and a bottom end and its just missing a top end i.e. intake carb, distributor. if so all of that will go right on the 350 and u can just bolt it all right in to your car.

give me the status of the 350 and i will give u a definite answer.

[Irocz28chic]

I have no idea on the year of the 350 block...and the block is bare but I do have a set of 350 heads. And out of curiosity....will LT1 heads work? I have a set of them too but they are the iron ones like off of the Impalas. I also have a 383 crank but have been told that it wouldn't work unless I changed the cam.

[MonteC]

ok so u just have a bare block? no crank no pistons no rods no cam correct? ok well if u have the time money and know how, go ahead ands put that crank on there, buy some new pistons and rods, dont reuse pistons or connecting rods. any cam will "work", so ya u can use that 305 cam but it would suck power wise.

heads:
when u say lt1 u mean second generation sbc? dont use those, infact its impossible to use gen2 heads on a gen 1 motor like the one u have, b/c the gen 2's have a reverse cooling system, very different from the gen 1's.

use those 350 heads u have.

my person advise would be to keep that 305 in there and wait until u get that crate engine, your gonna spend more than u want to on building this 350, its alittle more involved than u think.

[Mcdamit]

No actually monte that was far from parroted as for the year of the 350 look up its casting number. Its usually on the rear of the block driver or passenger side or on the upper section of the block where it mates the tranny, and monte thats all i was gonna help her with. And find something wrong with what i just said.

[Irocz28chic]

Ok correction...was told that I would have to change the rods. The LT1 heads have a reverse flow too huh? Hmm....I am so full of questions that I don't know where to begin. Basically, I ran the shit out of this motor...when I tore it down I noticed a burn mark on the inside of one of the cylinder walls(assuming thats from where it overheated severely) and a couple of the rods were sticking....the motor was gunked up(dont think the reneck kid knew how to change oil either) I couldn't even get my pinky through any of the ports in the intake. It was bad. My biggest mistake was not tearing down the entire motor....stupid stupid me.....I only went as far as the heads. I do have the option of a big block but am not ready to even attempt that one.

[MonteC]

Originally posted by Irocz28chic
Ok correction...was told that I would have to change the rods. The LT1 heads have a reverse flow too huh? Hmm....I am so full of questions that I don't know where to begin. Basically, I ran the shit out of this motor...when I tore it down I noticed a burn mark on the inside of one of the cylinder walls(assuming thats from where it overheated severely) and a couple of the rods were sticking....the motor was gunked up(dont think the reneck kid knew how to change oil either) I couldn't even get my pinky through any of the ports in the intake. It was bad. My biggest mistake was not tearing down the entire motor....stupid stupid me.....I only went as far as the heads. I do have the option of a big block but am not ready to even attempt that one.

pm me ill answer your questions.

just dont listen to mcdamnit.

[Mcdamit]

monte, she can use the cam if it is capable of bolting in, she wont make great power but as long as it isn't a peanut cam she still will put out around as much as an L98. As to reusing the rods, if they clean up nice and are still straight and true, why spend the money. Thats me, you can get decent pistons for $4-500

[Irocz28chic]

Originally posted by MonteC
ok so u just have a bare block? no crank no pistons no rods no cam correct? ok well if u have the time money and know how, go ahead ands put that crank on there, buy some new pistons and rods, dont reuse pistons or connecting rods. any cam will "work", so ya u can use that 305 cam but it would suck power wise.

heads:
when u say lt1 u mean second generation sbc? dont use those, infact its impossible to use gen2 heads on a gen 1 motor like the one u have, b/c the gen 2's have a reverse cooling system, very different from the gen 1's.

use those 350 heads u have.

my person advise would be to keep that 305 in there and wait until u get that crate engine, your gonna spend more than u want to on building this 350, its alittle more involved than u think.


I was planning on buying the 350 HO crate motor.....so now I ask....build the 350 or just order one? I would much rather be able to say, yeah we built that instead of aying we just bought the motor and put it in but at the same time that sounds easier. If I can build this one for about the same price then that's what I would rather do and I guess I could suffer a little longer on not driving it....besides the LS1 is nice. ;) Eventually, I wanna kick my husbands ass.....at least off the line....yes I plan to spray.

[MonteC]

Originally posted by Irocz28chic
I was planning on buying the 350 HO crate motor.....so now I ask....build the 350 or just order one? I would much rather be able to say, yeah we built that instead of aying we just bought the motor and put it in but at the same time that sounds easier. If I can build this one for about the same price then that's what I would rather do and I guess I could suffer a little longer on not driving it....besides the LS1 is nice. ;) Eventually, I wanna kick my husbands ass.....at least off the line....yes I plan to spray.

sure its fun to build your own and to say "yeah i built that". personally id go with the crate motor if i had the money.

if youve got the time and the know how and the right tools go ahead and build one, use the block u have, and if your on a budget those 350 heads u have will work. make sure all of the proper machine work is done to the above mentioned.

ok now, if ur planning on using nitrous on this engine then DO NOT reuse the 305 rods, personally i wouldnt reuse them anyway. go out and spend the money and buy a forged bottom end kit from summit or jegs or a reputable speed shop.

then a good cam, and intake and carb and on and on and on.

its easy to spend a ton of money on this engine build up, i never know when to stop.


how about this tell me what u want to reuse and ill tell u weather or not u can and if u cant reuse it ill give u a good recommendation on what to replace it with.

[nightrider]

To get some other opinions in here...

I would build an engine before I bought a crate motor...you can just get exactly what you want that way. Also no decently priced crate engine has any forged pistons in it.

If you're just interested in beating on an LS1 and you plan to spray and you want to do this cheaper than that 350HO which costs 2400 dollars.

OK so...

rotating assembly.

PISTONS
Go with some cheap forged TRW's. Summit sells some for $35 each, that ends up being about 280 dollars


RODS
Grab some eagle SIR I beams.
If you want to stay at a 350, get the 5.7inch; for a 383 get the 6.00.

These are not clearanced to run on a 383, you'd have to get a shop to do it for you. or give it a try. If you want to run a 383, you have to clearance the block as well. That i wouldn't pay someone to do, but the rods i might.

They are good to 500hp or more even and cost about 250 dollars.

By the time a shop does the clearance work on them, it might be more economical to just buy some Eagle H beams. These are good to something like 800hp but are 400 dollars. However, they are designed to clear when used in a 383, no clearancing required.

CRANK
i guess you've already got a 383 crank so i'd go with that. You're not going to break any of the aftermarket cast cranks at the power levels you desire...so as long as its not a stock 400 crank, go with that. Make sure you get it checked out by a machine shop of course.

Some good bearings, some "high performance" rings (you can go file fit if you feel comfortable with doing it) and you've got your bottom end covered.

So using your crank, lets say it just needs to be turned

35 dollars to have it inspected
280 dollars for pistons
400 dollars for the 6" eagle H beam rods (lets splurge so you have less work for the machine shop and you'll trust yourself throwing that extra bit of nitrous at it)
$200-250ish for rings and bearings

$915-965 dollars.

Compare that to a summit rotating assembly which costs 1400 dollars and gives you the cheaper I beam conencting rods but also a 70 dollar flexplate and you're still coming out way ahead.

either of the assemblies would need to be balanced, factor in another 200ish for that and possibly a new flexplate for 70 dollars. you probably want a new harmonic balancer as well for about 80 bucks.

OK so...
i'm assuming the 350 block is an older two piece rear main seal (make sure your crank is for the same type of engine) and therefore it'll have a flat tappet cam. Lucked out here in terms of price. Brand new cam complete with lifters will be only about 150-200 dollars depending on if you want to pay for a name or not.

moving up to heads...
you could go with some vortecs. these can be had with upgraded springs for about 650 dollars new. They are nice heads. same thing as on the 350 HO.

you could go with some iron pro topline lightnings. I am running these on my car though they aren't as cheap as they used to be as summit stopped carrying them and another one of their big distributors seems to have disappeared. I got my set for 800 shipped to my door. they are 180cc runners and have advertised flow numbers very close to the godly AFR heads...tehy don't generally live up to those advertised numbers unfortunately but they are still a very nice head and a VERY VERY NICE head for the money.

INTAKE
going with vortecs and the carburetor i'd run a edelbrock edelbrock performer RPM Air-Gap Intake. these are 225 from summit
if you really really want to convert back to fuel injection (i'm not so sure you do because it may be such a hack job from the de-installation of TPI that it'll take a hell of a lot of work to fix it up) then you're stuck with a vortec TPI setup for now, though they are going to release teh stealth ram for vortec heads soon IIRC.





machining work is about
300 bucks to get it dipped, bored to .030 over with a guide plate and your cam bearings installed.

I assume you'll put this together yourself or you'll find a friend who knows what he's doing.

965 rotating assembly
175 cam
700 vortec heads with upgraded springs
225 intake
500 or so to include boring, dipping, cam bearings and looking over your crank as well as balancing the lower end
2565 total


i left out pushrods and rocker arms. you could reuse them if you were really inclined though a new set wouldn't be that much.

this worked out to be the a little more than that crate motor, except you'll need a few more parts than the little ones i've listed and it may well nickle and dime you for another 200 dollars yet.

Hmm, that 350HO really doesn't seem bad at this point but keep in mind...

this is a 383
this has forged pistons and not hypereutectics like the HO and is therefore much more nitrous friendly
and this has 150 dollar more expensive rods in it

So really the price works out. oh and this motor with the right cam could see quite a bit more than 330hp...375-400

we can help you on cam selection...i just didn't want to go looking for it at this point. its late, i need sleep and i wrote this up instead of working on a seminar i have to give tomorrow...i'm glad i did though cause i was fed up with the work.

[MonteC]

ladies and gentlemen, there u have it.


btw the vortec stealth ram intake is already out.

[nightrider]

oh yeah? well there's the intake then

[Irocz28chic]

Damn, ya'll are extremely helpful! I appreciate it. Now if I went with that, what tranny would you recommend to put behind it. I am not too fond of the 700r4 due to the fact that I can't can't one working. :( Overdrive isn't really a necessity to me as I am already running high rpm's due to the 3.73 gears but once I change the rearend it will be 3.42's since that is what is already in it. Putting the 3.73's in the new rearend seems like a lot of hassle and I am not even sure that they are compatible. I have a little time to decide since I still need a hood and front gfx before it can be painted. Had the hood come up so the hood is basically fubar. I can't decide whether I wanna stay with the stock hood or go with the SS style hood. A guy at Thunder Racing has the SS style on his 91 and it looks great! Not really big on the cowl hoods, got one on the Z and I can't see over the damn thing. How do you all feel about gear drives? A guy here said he had one and it allowed the cam to walk....not sure how reliable he is though. As for the LS1, I'm not looking to whip his ass as I bought him a fairly aggressive cam for it for christmas(shoulda bought me one instead)....I would at least like to not get blown away. I would be happy with a low 13....but would eventually like to get more, naturally. Are big blocks worth the hassle?

[MonteC]

IMHO. big blocks are NOT worth the hassle, there big and heavy and require some modification to fit into a thirdgen. i prefer small blocks, currently im working on a 408 sbc, its gonna have the big block torque with the smallblock size. best of both worlds.

transmission.

im a big advocate of the overdrive trans, u can get your 700r4 built to hold up to the engine and it will last if its built right.


but if your postitive you dont need or want overdrive then go with a decently built th350.

if u plan on racing much you might want to look into upgrading your rear, im assuming its the stock 10 bolt.

as for the hood, go with what u like.

[Irocz28chic]

I guess I am kinda sore towards the 700r4 because when I got the car it had a slipping tranny. I knew that and figured I would just have it rebuilt since the price of the car was good. Spent over 1k on it and only got about 6,000 miles out of it. Don't know what is wrong with it. I had a shift kit put in, hit like a mofo while it lasted. I still have that tranny in storage.....might have it looked it while I am at it. It didn't slip or nothing. Alternator went out, pulled to the berm (shoulder) and changed it. Pulled back out onto the interstate and it wouldn't shift out of 1st. I have no luck. What about gear drives? What is your take on those? I am not trying to drive you nuts with all of the questions....I'm just trying to soak up as much info as possible.

[nightrider]

wouldn't bother dropping the money on a gear drive when a timing chain works in 99% of all the V8s out there.

If you truly don't care about an OD, get a TH350 like Monte said. The summit 600 dollar one will work. It worked in my car. I wouldn't buy a cheap convertor though. Spend your money there if you want to keep some remote chance at an efficient car when you aren't at WOT.

OD is fairly important to me however. I'd run a built 700R4 if you just want something you can bolt in and like autos.

I love OD, i also love manuals... monte knows this ;)

I'm doing a T56 in my car. its a bit of a big swap and while i have yet to do it, it doens't seem all that bad from the readings.

[Irocz28chic]

I am a munual person myself.....but I really don't wanna deal with the hassle of converting it just yet. The car won't be driven to far....because when we do go far we take the Z. The IROC will basically make short trips at a time and the track isn't too far from here. :) Now I will probably keep the 700r4 just in case I wanna take the car home for my dad to do the interior....which is 1000 miles away. Sounds like a pain in the ass.....but that damn 700r4 still has me mad. And that wasn't the only 700r4 to give me hell.

[krazymonkey]

You guys are all missing the point Irocz28chic was trying to get across to begin with. She is trying to put a motor together just to get around while she waits to get a nice crate motor. Therefor, what in God's name is the point of going with all new expensive stuff? If I were you and this were the goal I had in mind, I would reuse any and everything I had that I could reuse for the moment. This goes for the crank, even if you have to have it machined, the cam and lifters if the aren't too worn, I would say pistons, but you are going for a 350 instead of the 305 and the bore isn't the same. You can even use the 305 heads if the blocks are within the correct year ranges and you end up with a little bit higher compression ratio due to a smaller combustion chamber. Use the connecting rods, also. Really, all you will need if everything is still serviceable, is a set of pistons and a $60 re-ring kit. Everything else should be ok to use. If you decide that you just want to build the 350, the a little trick that I have learned is if you use a decent cam, you'll lose about 12 horsepower at the flywheel between the 305 and the 350 which is almost nothing at all worth mentioning as far as rear wheel horsepower. If you can afford it, get a set of Dart II heads. The are well worth it and you'll be glad you did. You can get them anywhere between $650-850 depending on store and specials. I hope this info helps out.

[MonteC]

Originally posted by krazymonkey
You guys are all missing the point Irocz28chic was trying to get across to begin with. She is trying to put a motor together just to get around while she waits to get a nice crate motor. Therefor, what in God's name is the point of going with all new expensive stuff? If I were you and this were the goal I had in mind, I would reuse any and everything I had that I could reuse for the moment. This goes for the crank, even if you have to have it machined, the cam and lifters if the aren't too worn, I would say pistons, but you are going for a 350 instead of the 305 and the bore isn't the same. You can even use the 305 heads if the blocks are within the correct year ranges and you end up with a little bit higher compression ratio due to a smaller combustion chamber. Use the connecting rods, also. Really, all you will need if everything is still serviceable, is a set of pistons and a $60 re-ring kit. Everything else should be ok to use. If you decide that you just want to build the 350, the a little trick that I have learned is if you use a decent cam, you'll lose about 12 horsepower at the flywheel between the 305 and the 350 which is almost nothing at all worth mentioning as far as rear wheel horsepower. If you can afford it, get a set of Dart II heads. The are well worth it and you'll be glad you did. You can get them anywhere between $650-850 depending on store and specials. I hope this info helps out.


hey how about u shut the fuck up you cheap douche.

[nightrider]

we told her not to build a crate engine....or that she should atleast just save her money and get the crate engine from the beginning. There's no point spending money throwing together a POS engine just so you can get around

[krazymonkey]

It all just depends on what your priorities are. You always have to ask whether or not the person would rather the car just idly take up space or would they rather it be drivable for the moment. With me, I would rather drivability be my first concern. Then, I would save up and buy the parts I want individually, which is exactly what I am doing with my '82 Z28. Right now, I am running on the TPI setup that came out of an '86 IROC. It's a great motor and transmission, but it's shit compared to what I am building. I put it in there specifically so that I could drive it whenever I felt like it while I was building the other. Once I have it build and installed, I have another motor and transmission in great condition ready to go into whatever I see fit later down the road, so I don't see that as a waste either.