i wouldn't mess with anything that sacrifices low end performance (i'll buy a honda when i want a honda thank you). headers fit lousy and rust out quck. the stock tbi
manifold flows better than the turbo exhaust manifold. you don't want to get bigger than 2" diameter exhaust without forced induction on a 2.2/2.5 or you will hurt throttle response and low end. change out the converter and muffler for higher flow units.
unless you are building a hi-po n/a engine for a special racing class, you might as well go with a turbo-intercooled setup instead. the practicality of an n/a motor in stock trim is it runs fine on 87 octane and anything with serious power will require premium. best way to get more air into the engine is convert it mpi for an extra 10hp and better high rpm breathing (more than enough for a naturally aspirated 8 valve).
if you have a 2.2, switch to a 2.5....more power for the same gas mileage. and the advantage is a 2.5 can turn a softer gear for better highway driving thanks to more torque.
got an auto?, get a stick. quicker acceleration AND better highway than a 3 speed slushbox will give you. better gas mileage also thanks to an overdrive.
my 86 aries wagon will eventually be 2.5T2 powered but for now I will probably just throw in the 2.5/3spd from my 91 dynasty. planning to use it to tow a couple cycles to bike week in daytona next spring and a 3000 mile round trip on unleaded regular is going to be expensive enough. i think i will wire in my 90/91 sbec
harness so i can run mpi with a mexican cal. i will also have a lockup converter thanks to the newer trans and wiring.
was thinking a 2.60 final drive (10% less rpm cruising) with a 3000 stall turbo lockup converter (more torque multiplication) might work. but will probably just keep the 3.02 gears for better towing on hills. the tbi
2500 stall converter might not maximize power but it is a little more drivable and would save some money as most of my budget in the next few months is going into bodywork.