why are the 75,76 heads considered junk?do they flow just terrible compared to say a 72 or 73 head?if its just the large chambers 8:1 cr aint so bad on pump gas.iknow 9:1 would be nice but i have a set of 76 heads.would a mild shave of the heads help any?i was planning on a poston s divider intake.would that be a waste of time with 76 heads?...thanks
Bigger chambers which lower compression is the main reason for low popularity on these heads. Shaving would help some, personally, I would start with a good year head and spend the dough on them. That way, if you ever decide to sell them, you could regain most of your investment. In the quest for HP, every little bit counts to me. Good luck.
I agree they are 78cc compared to 70 heads at 68cc, the biggest power gain you can do is raise your commpression. i would guess the difference in power between 8 to 1, to 9 to 1,could be 60-70 ft lbs torque and 40h/p. most cars on here i see run 9.5 -1, that makes for a pump gas car and still have desent low end torque. saving the heads, besides cleanup does very little. just my 2 cents
The chambers in the 75 heads are fully open while 74 and older heads had a quench chamber desigh. The 75 heads had a volume of 77 cc while my 72 heads were 73 cc. These open chambers cause flame to have to travel further outward before it begins pushing downward. That is a condition that can be affected by increasing timing. Compression is the only true down side. About a 1/2 point from 72 heads to a full point from 70 heads. According to all I have talked to here, these heads have to be run on a 75 or 76 block only, due to larger water jackets.
