hi, ive been reading and it seems that 351 heads work work on a 302 and actually help it alot. is there anything enlse for a 351 that would work in a 302?

 

What vintage motor are you talking about? Starting somewhere around the mid '70s both motors used the same heads so there are no gains in swapping those around. Any 302 built between 1977 and 1994 could really use a cam upgrade, it is the single best upgrade to increase HP and torque.

 

it is a 90 302, maybe that is why i keep reading that the heads will work off of a 351 . ok in that case is there a difference between gt40 and gt40p heads

 

Yes, GT40 heads flow about 25% better than the E7TE heads on your motor right now and GTP heads flow about 30% better, but only regular GT40s are a direct bolt on the P heads will require exhaust mods and custom plug wires.

If you are dead set on changing the heads definitely change the cam while you got it all apart otherwise you will see very little gains from the heads.