question about 2 different 350's - NJFBOA - Home of New Jersey's Camaros and Firebirds

camaros_4life34 · 02-05-2009, 03:44 AM

i have a 350 with good bottom end but a junk top end it came out of a 1982 blazer and i have a 350 with good top end but junk bottom end its out of a 1995 chevy 1500 one is carberated one is tbi i know i need to change the heads with the intake to make it work but do i need to change the cam as well as ive been told the cams were different in the older 350's if neone can help plz fill me in on what i need to know im goin to start this project later on today

LTb1ow · 02-05-2009, 07:24 AM

1995 350 = LT1 no?

WildBillyT · 02-05-2009, 08:24 AM

Quote:

Originally Posted by Shownomercy

1995 350 = LT1 no?

I don't think so...

The 1995 motor should have a roller cam in it. Your other motor will not.

LTb1ow · 02-05-2009, 09:56 AM

So in 1995 GM made both GenIIs and GenIs?

The Fixer · 02-05-2009, 10:05 AM

Quote:

Originally Posted by Shownomercy

So in 1995 GM made both GenIIs and GenIs?

Yep, trucks and vans got the Gen1 motor, while the cars got the LT1 and L99. His motor is out of a truck, so it's a Gen1 motor.

To the OP, you can put the new heads on the older motor, but you ~might~ need to use the old pushrods as well; I'm not sure if there's a difference in the length between the two. Also, what's your plan for induction? If you're going to run a carb, the intake bolt pattern is different between the heads on the '82 engine vs. the '95 engine, so you'll need a different intake manifold. The exhaust should bolt up just fine.

LTb1ow · 02-05-2009, 10:06 AM

Quote:

Originally Posted by TPI Monte SS

Yep, trucks and vans got the Gen1 motor, while the cars got the LT1 and L99. His motor is out of a truck, so it's a Gen1 motor.
.

Thanks!

To the OP, sorry for the hijack.

camaros_4life34 · 02-05-2009, 10:07 AM

no there 2 different generation motors the 95 is a 5.7 liter but is equivilent to a 350 its a tbi engine the other is the old school carburator 350 i know that one has solid tap lifters i tore that one apart allready this morning im waiting for the other engine to get here so that i can get that one torn down id just like to know if i do have to change nething so i can get the extra parts needed ahead of time

camaros_4life34 · 02-05-2009, 10:09 AM

no im goin to keep it tbi

Stevoone · 02-05-2009, 10:43 AM

Aren't the 86 and older blocks 2 piece rear mains? And I think the newer blocks also came with smaller flywheels. When I put my 383 in the T/A I had a problem with he crank flange, the new style flywheel wouldn't bolt up to the old design crank.

FBODS4EVER · 02-05-2009, 11:29 AM

95 is probably a roller motor and the 82 is a flat tappet. long story short. you can use the 95 top end roller set up on the 82. but you have to use the entire valve train. cam, lifters, push rods, etc. also if useing the older block. you will need a hydraulic retro fit cam. as the block was originally a flat tappet block. the reason for the need of a retro fit cam is the cam cant be allowed to move forward or backwards in the engine. Flat-tappet cam lobes are ground at a very slight angle to prevent the cam from moving. Roller cams cannot be machined that way, so a roller-cam button is employed to limit cam movement. The spec is 0.003 to 0.005 inch. This is because load from the distributor drive gear. tries to push the camshaft rearward, which usually retards ignition timing. The button prevents this from occurring. hope this helps.

BonzoHansen · 02-05-2009, 01:29 PM

The oe roller setup will work in a non roller block?? What about the spider bracket that keeps the lifters in place?

WildBillyT · 02-05-2009, 02:06 PM

Quote:

Originally Posted by BonzoHansen

The oe roller setup will work in a non roller block?? What about the spider bracket that keeps the lifters in place?

I agree. I was under the impression that you have to use a retrofit roller setup in a pre-roller block.

7998 · 02-05-2009, 02:40 PM

Quote:

Originally Posted by BonzoHansen

The oe roller setup will work in a non roller block?? What about the spider bracket that keeps the lifters in place?

I believe you have to drill the block to accept the the roller lifter brackets. And I'm stumped on the top end fitting, damn I think it will

The Fixer · 02-05-2009, 02:43 PM

Quote:

Originally Posted by Stevoone

Aren't the 86 and older blocks 2 piece rear mains? And I think the newer blocks also came with smaller flywheels. When I put my 383 in the T/A I had a problem with he crank flange, the new style flywheel wouldn't bolt up to the old design crank.

If he used the original flexplate and starter to the '82 motor, it shouldn't be a problem. Also, there's no need to swap the cams and stuff. He can use the cam and lifters as is in the '82 motor, he just needs to use the correct length pushrods (they're probably the same) and use the self-aligning rocker arms that are already on the '95 heads.

Pampered-Z · 02-05-2009, 03:02 PM

Without doing allot of checking, my first "guess" would be you shouldn't need to change cams, they probably aren't that different between carb and TBI. Nothing that would cause any real issues.

What are you using the engine for? What you may need to look into is the CC of the heads. If the old heads were big chambers and the new ones small chamber you might want to verify you're not pushing the compression ratio above regular grade gas, or even above pump gas?

When you pull the engines apart check the piston style, may need to check piston to valve clearance due to piston design? Probably not an issue, but you may want to check if one engine had the 4-valve reiefs, and the other 2-releif or flattops?

Like others said, check pushrod lenght, probably standard SBC flat tapped PRs, Also check the holes for the intake aligne, that might be the issue or at least your need to purchase an intake that matches up. Also double check all the fittings sizes and mounting holes are in the same locations so that all the brackets bolt up correctly.

Keep us posted, sounds like a cool build.

JB

NJSPEEDER · 02-06-2009, 04:39 PM

All of the Gen1 cams can be interchanged. The lifter bores are identical, the only thing that changed was adding and tapping the lugs on the center rib for the roller lifter spider.

The factory roller lifters are actually pretty good pieces. If you are staying hydraulic, keeping them and going hydraulic roller instead of flat tappet will give you a little extra power and a bit better idle quality.

Other than that, most of the casting and metallurgy quality is the same from the 80's and 90's.

FBODS4EVER · 02-10-2009, 04:22 PM

Quote:

Originally Posted by BonzoHansen

The oe roller setup will work in a non roller block?? What about the spider bracket that keeps the lifters in place?

never said oe. i stated retrofit cam.

camaros_4life34 · 02-11-2009, 07:54 PM

ok guys i got both engines torn down. believe it or not they both had the same cams in them, but the pistons r cut different. the 82 is a flat top the 95 has cut outs in the piston, kinda like a butterfly. Is this cut out for the valves, or something the factory did as a compression design?

Tru2Chevy · 02-11-2009, 08:16 PM

both have the exact same cam installed in them?

- Justin

camaros_4life34 · 02-11-2009, 08:43 PM

believe it or not yes they do

BonzoHansen · 02-11-2009, 08:59 PM

Quote:

Originally Posted by FBODS4EVER

never said oe. i stated retrofit cam.

and lifters & pushrods and everything. None of the later model OE stuff will work.

camaros_4life34 · 02-12-2009, 07:56 AM

everything cam, pushrods, n lifters there all the same what do you think about them apples lol

Tru2Chevy · 02-12-2009, 01:50 PM

So was the TBI motor not a roller setup?

If so, someone has already had it apart and converted it to a flat tappet setup....

What cam is in both motors?

- Justin

camaros_4life34 · 02-12-2009, 04:23 PM

just a regular flat tappet the top end on this motor has been done befor when i took it apart the gaskets were still lookin new (color blue) id say from lookin at the gaskets they only had between 20 n 30 thousand on them. im switching cams out in them though even though they r both the same do to the fact if it has been switched from roller it may very be an aftermarket cam....... i hope so