I recently picked up a pair of 302 casting head near me for pretty cheap.
Is it worth swapping them out on my car (original motor with a new 4 barrel and Weiand ac+) if I used a thinner head gasket, also why does ever set of head I find always have the rocker shaft and arms always pulled.
Thanks and merry Christmas.
Merry Christmas to you and yours!
My take on the 302 heads are kind of like which side of the quarter is shining better. If your heads pass inspection, the best way to prep the head for a noticeable gain over the other head is to at the very least have the shop race prep them in the valve area, with or without larger valves. If you move to larger valves, which would be good, they will take them without issue. The valve size depends on what your doing with them as I have had really nice results on street vehicles with stock valves and 360 (1.88) intake valves, and a bowl porting under it.
The difference between the 302 and the earlier heads are the ever so slight changes made through out the years ending with a better exhaust port. It is a minor advantage. Which also works better with a 1.60 valve and a bowl porting under it.
There isn’t much gain with bigger valves without a bowl porting under the valves. It’s yhere but IMO not worth the small gain and expense unless ported.
The rocker arm shaft pedestals are in a racers perspective in the right position. Look for B3 for his rocker arm geometry correction kit. His kit works great and even better when you start swapping cams and changing rockers around. The OE manufactures rocker position is fine enough for stock specs and good longevity but far from what is ultimately the best.
For a compression ratio, you’ll need to know all the specs of where the piston sits in the hole, cc valve relief amount, gasket thickness and diameter and cylinder head cc amount. Plug them into a program. FWIW, your not going to notice a 1/2 point of compression ether way unless it is up and regular gas does play nice.
