Quote:
Originally Posted by BRUTAL64
Valves are too small. Need chamber size.
Alum heads are really good for forced induction. The aftermaket heads will have the latest "good" chambers and will take more boost than cast iron factory. 
With only 4 head bolts per cylinder we will need to think "O" rings or a VERY special head gasket. I have a DVD on this somewhere. |
As long as we use Fel Pro MLS gaskets we should be fine without O-rings. I'm running a set of AFR 165s on the Cobra with 9.2:1 compression and 10psi of boost and haven't had any issues with them.
As for head size that depends a lot on the specs of the cam. Joedls, do you have any idea what the specs are on that custom grind cam? We are talking about only 302ci so we don't want to go too big unless we are going to rev it really high (above 6500rpms). And if that's the case then we need to ditch the hydraulic roller and go to a solid roller. Hydraulic rollers in the 5.0 are only good to about 6500rpms. I think something around 185cc to 190cc if the cam has 220 at .050 or more. If the cam has less than 215 at .050 then something in the 165-170 range would work well.
Ben, I'd pass on that 8.8. One, it has drum brakes and two, it only has 28 spline axles. Also, I'm fairly sure that it will have to be narrowed to fit under the RX7 but you could measure and see. If you want to go with an 8.8 get one from an Explorer that already has disc brakes and 31 spline axles.