What is the difference with the L98???

[Guest Anonymous]

I have built a few Chevy SB before. Nothing too extreme, but I sure had fun!

 

Here is my question: What is the difference between an older (1972) Small Block and the 1988 L98? I have searched online with no luck.

 

The reason I am asking this is to find out if a L98 head will fit on an older block. Also, I want to know if a L98 cam will work in an older SB.

 

From what I have read, it looks like people have installed L98 heads on older blocks, but I would still like to know what the difference is.

[Mike C]

The L-98 heads work just fine but require center bolt valve covers. The AL ones use a standard small block intake pattern. There are both aluminum and iron heads depending if it is on a Corvette or Camaro. And the 85 'vette and early '86 cars have iron heads. The later iron heads use the late model intake pattern (pre-vortec). The 85 and 86 Camaro motors have flat tappet cams which will work in an older block. The 86 and up 'vetter motors and the '87 and up Camaro motors have hydraulic rollers. The GM roller cam needs to be used with a factory roller cam block.

[Guest Anonymous]

Mike,

 

Thanks for clearing that up. I am looking at getting the LPE SuperRam DFI system for a small block. On their web page they only have the L98 DFI system.

 

So, I can use the L98 DFI system with AFR 190 L98 Heads on a older block?

 

And I can use a L98 Cam with Hydraulic Rollers?

 

I think things are starting to make more sense now... Thanks again!

[Guest heinera]

I am pretty sure you can't use stock l98 roller lifters in an older block. There is no provision for mounting the brace in the lifter valley that keeps the roller lifters from spinning in the bores. You could use some aftermarket lifters, you know the kind that are connect in pairs. But they are expensive. Like $250+.

[Guest Anonymous]

Okay, so let me get this straight. This is what I understand:

 

1. Any L98 head will work on any older SB.

2. Any L98 Cam will work in any older SB.

3. L98 lifters don't work in older SB,.

4. A L98 head needs to have an L98 intake manifold.

5. L98 engines have extra mounting brace to hold the lifters in that the older SB doesn't have.

 

Does all this sound about right? If so, looks like I understand it all now. (Except for the fact that I still don't know what the big differences between the two blocks are...)

[Guest thepenguin99]

I think you got it. =)

 

One other thing...you can drill an older intake to fit l98 heads. Also, some L98 heads were angle plug and D shaped port (88-91 I think) so you would want different headers than older heads use.

 

hmm as far as block differences between older sbcs the 86+ blocks are 1 peice rear main seals and have provisions for roller lifters.

[Mike C]

The non-roller L-98 cam will work in a non-roller block, but the GM cam and lifters require a special walk plate and chain so will not retrofit. It is not a good cam anyhow. I'm pretty sure the aluminum L-98 heads don't use the '87 and up intake pattern that the iron heads used but kept the conventional pattern, correct me if I am wrong.

[Guest Anonymous]

First off, I want to thank you guys! You have helped me learn a lot.

 

The cam I want to use is LPE L98 roller cam. It isn't a stock L98 cam.

 

Specs:

211/219, .530/.560 (1.6 rocker) at 112

Here is the link:

http://www.lingenfelter.com/lingenfelter/product.asp?dept%5Fid=24&pf%5Fid=489

 

The reason for picking this cam is because it is matched for the Accel SuperRam DFI system that I have my eye on. But it is only for the L98 SmallBlock. This is where I started running into questions.

Here is the link:

http://www.lingenfelter.com/lingenfelter/product.asp?dept%5Fid=16&pf%5Fid=63

 

So I was thinking that with the L98 intake I would need L98 heads too. Air Flow Research sells two versions of their AFR 190. One is for the Small Block, the other is for the L98. So I figure I need the L98 head to match the L98 intake.

 

Would that L98 cam work in an older SB? They have one for roller and one for non-roller. However, the non-roller has different specs:

214/224, .472/.496 at 112. (Also using 1.6 rocker)

 

Would either one of these cams work in an old SB? Any thoughts or their differences?

[Guest heinera]

Yes an L98 cam- roller or non roller, will work in an old block. However you cannot use oem hydraulic roller lifters because as mentioned above there is no way to mount the plate that keeps them from spinning (it needs to mount in the lifter valley). You could use aftermarket hydraulic lifters with the bars that hold them together in pairs. But as stated before, they are expensive... like $250 plus. You might be better off to get an 87+ block that has the mounting holes for the roller lifter guide plate in the lifter valley. And get used oem hydraulic roller lifters.

 

Does that make sense...?

Thanks, ADam

[Guest Anonymous]

Thanks for the info. That raises another question, if I get a non-roller cam, will that still work with the L98 heads? Or if the heads are for a L98 (made for roller) then must I use roller cam?

 

One other question: If I have an L98 intake manifold, how hard is it to mount it on non-L98 heads?

 

Thanks again guys, you've helped out a ton!