Probably the cheapest and biggest gain is from porting the exhaust logs and the Y pipe.
On my 85 3.4PR I ported the heads and all the exhaust and I'm getting 36 on the hwy in the summer and 24 in town driving.
I don't know how much of that might be from the heads but most is problaby from the exhaust..
Pictures are the second page of my post if you want to see pics. http://www.fiero.nl/forum/F...2/HTML/072303-3.html