i have a 1988 4runner everything is stock but i am running 31 inch tires. my question is i am looking to do a complete stainless exhaust with a header. with a 22re is a 2 1/2 inch exhaust going to give me a gain or loss in horse power?

 

You'll be able to feel a difference not a kick in the pants but a dfference. Stainless sounds expensive. I did a thorley tri-y header, Hi flow cat, glass pack, with 2 1/4 through. they pipe from glasspack back cost me $45 installed the rest I did (first time welding so more holes than swiss cheese).

 

i think 2 1/2 will be too much...2 1/4 seems to be the magic number..remember backpressure is your friend on the R series motors...im going with straight pipe 2 1/4in pipe..through dual 3.5" stacks behind the cab of my '80 4x4 shortbed yota im hoping its gonna be loud...this isnt for looks..its for functionality...because now i can go in deeper water...because my exhaust wont be under water..

 

I have Downey's 2.5" exhaust and the great big cone filter. It's loud but it sure helps that wheezey motor perk up. My truck now takes less RPMs in 1st gear to get moving.

Lots of folks say 2.25" is the way to go. I have no complaints about the 2.5" system except that its loud.

 

since when do 98s come with 22re's ?

i thought they came with 2.7's ??

 

I went from bone stock to LC eng. Header and 2-1/4" system with Magnaflow muffler and Cat. it isnt a HUGE difference in Power, but you'll notice more, pep and it can lug a taller gear every now and then. I've also got 31's too. I think you'll like it, but dont fool yourself, your ride will be a little more thirsty.
If you can do Stainless all the power to ya!