tgates

i have a 1991 camaro z28 5.7 tpi stock with just exhaust and jet stage 2 chip. i want to change the heads and i dont know what would be the best choice, or should i do something esle first? any ideas?

teke184

bolt ons first over heads.

get it breathing better.

assuming you keep the stock TPI....port the plenum and possibly add a bigger TB.
open up the air box for less restriction
rebuild the ignition for a little more power
headers are always a good upgrade (didn't say what kind of exhaust you had)

heads are a good upgrade, but with the stock cam you won't see much. swap in a bigger cam, throw some heads on it, and get a custom tune (a must).

tgates

ok heads i'll do later down the road. and i just have stock manifolds just a cat back magnaflow

tgates

what do you mean "rebuild the ignition"?

Rice Killer87

Teke probably means put a higher volt coil on it, new plugs, wires, cap and rotor.

Headers should be your first mod.

Second mod thats best for the money is an adjustable fuel pressure regulator and a cheap pressure gauge to set FP with.

Save up your money to do heads, cam, stall, and gears near the same time b/c they all need to work together. Then some more money for a custom chip.

EDIT:

Definately read up on gutting the air boxes underneath the air filters also.

mpilarZ281992

New headers offer more bang for your buck. I used Hedman shorties ($150 only from summit and Y pipe ($100)) and im happy with them (I removed the A.I.R.). Then I would go for induction changes such as K&N air filters, gut the air box (at least remove the damns and drill some 1/2 holes), port the plenum, air foil, adjustable fuel regulator. Then more bolt ons could be bigger runners (i have SLP), port the intake manifold to breath more.
Currently I am installing Trickflow heads ($1200 from summit) and ZZ4 GM performance cam (around $200) with a 2400 stall converter ($350). But this can get expensive, especially if you have a shop do this. My advice is learn to do the work yourself and you would be able to afford more, as well as getting to know your car. On these TPI cars, its not just a couple of "bolt-ons" that will make you happy, its a combination of little things that add up. Good luck on your mods.

tgates

i have dual cats and its hard for me to find headers and y pipe for under 500. could i buy shorty headers and reuse my factory y pipe

Kevin91Z

No, headers and y-pipe are a matched combo and you must buy them together. Nobody's headers will bolt to any other y-pipe and vice versa.

Head over to thirdgen.org and search the Exhaust forum for "dyno don headers". He is my father and he makes some awesome headers with a dual-cat y-pipe. They're a little more than $500 though, but they're very worth it.