i was wondering if a s4 radiator could fit on a s5 rx7? i have a 1991 na rx7. and if it can then what would i have to do to fit one on?

 

Yes, but there will be nowhere to fill it from. You would also need to swap on the coolant filler neck from an S4. S5s have the filler neck on the radiator itself.

 

Much easier to just use a s5 one

 

if you're replacing the radiator you might as upgrade while you're at it to an all metal dual pass radiator
https://www.radiatorbarn.com/search....oduct=radiator
something cheap from this site (or many others like it) will work fine on an NA

 

well alright, thanks for the info guys!

 

If you go w/ a new one, you can pick up a 53mm dual pass Koyo w/ mounting kit for $305 here: http://www.absoluteradiator.com/Prod....asp?idProd=18

Stock shroud & fan fit just fine, and all you need is a roll of ~1/2" foam tape to seal the gaps. Cools far better than a stock rad too.