i have a 91 rs with a 305 tbi. all stock with over 260,000. i was reading some stuff about the 081 heads would bolt right up and flow much better. i was wondering would it be worth it or not. what kinds of gains would be expected from these heads. i know where i might be able to get these heads cheap but would like to know would it be worth the money and time to do this. thanks for any help.

 

Those heads will bolt on, but don't know if the exhaust manifolds would bolt to those heads - the TBI ex manifold is different than the others, and those heads are from a carbed car I think.

You have to also be careful with how much modding you do to a TBI car - there's not very far you can go without custom chip tuning. I swapped out 416 heads that I ported/polished in my TBI car, along with new intake and LT1 cam - and after having someone tune chips for 3 months, I finally ended up with a barely running car again. I could have swapped over to carburated, and she would have screamed - but the TBI chipset has many limitations - there's not much beyond the Free TBI Mods and exhaust you can do before crossing that 'line in the sand'.

 

The 081 i believe are the 305 TPI heads and yes they are a straight bolt on head. Your exhaust will bolt up to them just fine. The way i understand it is you wont get much of an improvment over your TBI heads with out porting the 081. It might still be worth getting 081 and having them ported and having the valve guides cut to accept a larger cam. It's also recommended that you replace the pressed in rocker studs with skrew in one's as well. Id ask a machine shop to quote you on the labor and then make your decision if it's worth it or not.