Guys, what is the bigger restriction on the L98?

I've read that using headers will help but with an L98 that has the higher flowing exhaust manifolds and a dual cat set up the gain will not be all that significant.

The second being the intake. It seems more people think the TPI set up is the biggest restriction on these cars.

What are your opinions??

 

On a bone stock l98, exhaust is the biggest retriction. a set of headers and a cat back( probably a new converter if you have emissions) will do more for you now than intake mods. This is arguable, but my car went from mid 14s to high 13s leaving the intake alone.

 

Intake and exhaust are both pretty restrictive. The TPI is not adequate for the air the 350 needs at high rpm, and neither is the exhaust. All you can do is decide if you want to make it able to rev higher or maximize the torque you already have. The headers will help with that. I went 13.58@99 mph with a stock TPI with a 2200 convertor, 3.73 gears, and BFG drag radials. Either mod you do, whether it be intake or exhaust, will have the benefit be limited by the other. The heads are not much better than either the TPI or the exhaust so you need to consider that also. The L98 is a good combo and was designed to work together, equally flowing system intake through exhaust and no one mod will make it run like LS1 n/a.

Good luck,
Charlie

 

The area around the intake valve seat.

 

I've read that on a dual cat car that headers would not be as big a gain than on a car with a single cat. That and 350's came with better flowing manifolds than the 305's.

 

After exhaust, I 100% agree with the above statement.