I have a stock '92 Z-28 with 350 TPI . Gonna put on the Edelbrock Shorties . What size do I need ? Do I have to burn a new chip for the headers ? And I'm putting on the pulley kit . How much HP will the headers and pulley's give me ? ... AJ

 

Well, this subject of header size has stirred a lot of contreversy in the past, and I'm sure it will again...

I would say that unless you are planning on spinning your engine upwards of 6000RPM on a daily basis, the 1 5/8's are fine and won't cost you any low end torque, and will be easier to install.

As far as horsepower numbers I would estimate 10-20HP with the headers and another 5-10 with the pullies. This would be at the crank, not the wheels.

 

It depends. What do you finally plan to do? Are you going to stop there, run it for a couple of years and sell it or are you going to keep it?

 

I agree 1 and 5/8" are plenty for 95% of the cars on the road and will support 450hp easily, while keeping the torque numbers high...I've seen 350hp cars actually lose some HP and more tq going to 1 3/4" primaries. Primary size has a very similar effect on a motor as intake runners.

 

I concur with IROC and 90roc....unless you're runnin 400hp or more you really don't need 1 3/4" primaries and if you're much less than that they'll cost you quite a bit of torque. Stick with the 1 5/8". They should be good for 15 horse on a stock engine and prolly 5 more from the pulleys (at the crank)

 

Edelcrock only makes one size of headers, and that's 1 5/8". They used to have 1 1/2" and claimed that made more power. And then suddenly they switch to all 1 5/8". Hrm.....

I've got 1 3/4" headers on my car. Does 419 torque at the wheels, at 3400 RPMs sound like I've lost any low end?

But for a stock car, you cant go wrong with SLP 1 5/8" headers, or Hooker 1 5/8" headers. Just stay away from Edelcrocks, they're some of the worst made in my opinion. Do a search on this board and on the Exhaust board over at http://www.thirdgen.org/ for the reasons why.

No you do not need a new chip for headers. The stock chip and computer will compensate just fine.

Be careful with the pullies. Many people I know have reported problems with alternators and batteries after putting those on their car.