L98 intake manifold question...

[Edmond]

I just picked up Lingenfelters book on modifying small block Chevy's. Excellent book I might add!

The book stated that GM was going to do away with the 350 and the intake manifold was actually designed for use with a 305. Can anyone shed any more light on this?

I know Chris always says the intake manifold is one (if not the biggest) choking point for L98 motors.

Was about the stock heads for the L98's? How sufficient are they?

 

[-=Jeff=-]

Yes the TPI as a whole was built for the 305.. it will choke on a 350.

The base is smaller since it is the same one on 305s and 350s


As for heads, they were buld for the 350, but will not become a choking point until you increase the breathing of the intake and exhaust.

If you change heads, you will also want to swap cams. My best advice is to pick your components wisely as the combination is VERY inportant in getting the most power

 

[vader86]

Its true, it was designed for a 305 to increase its torque.

LT1 was the first GM manifold for a 350 bottom.

I believe the situation was that GM had decided to use the 305 with the TPI in the vette, then recanted that position and were stuck with the 305's intake. They didnt have time to design and test a new one.

 

[Tom73]

LT1 was the first GM manifold for a 350 bottom.

But the LT1 is a GenII engine not the "Classic" Chevy small block.

 

[vader86]

It is, and they dont make a manifold for the Gen I SBC.

But the fact remains, the LT1 manifold was the first for a 350 bottom.

 

[zerocool61]

Unchocke

So I got an L98, I got a 52mm TB, now how do I unchocke it?

 

[Edmond]

Re: Unchocke

So I got an L98, I got a 52mm TB, now how do I unchocke it?

You either port the existing L98 manifold, or you buy one of those high flow ones like the TPIS "Big Mouth."

If I do any work this winter, I am probably going to have mine ported since I won't do anything too radical.

 

[zerocool61]

Porting?

What about the "Mini Ram" from TPIS. I know I can't use my fuel rail and I need to get theirs but is the $1200 worth it? If you do port the manifold what does it involved?

 

[Edmond]

Re: Porting?

What about the "Mini Ram" from TPIS. I know I can't use my fuel rail and I need to get theirs but is the $1200 worth it? If you do port the manifold what does it involved?

Chris (69MyWay) and Jeff (C4 mods forum moderator) both use the miniram. I've have not heard a single bad thing about the miniram. Too costly for me but if money doesn't stop you, go ahead!:L:L:L

The miniram is just like the intake manifold for the LT1/4 powered Corvettes. It's breathing capabilities on the higher end of the RPM band cannot be duplicated with the TPI. It all really depends on what you want to do.