Big Block #518 cylinder heads ???

[4406v]

If I put a set of #518 closed chamber cylinder heads on a stock 72 440 or a stock 70 383 will these heads help increase compression? And will they help improve the power output of the engines? What kind of increase should I expect?

[Chryco Psycho]

The closed cylinder heads will bump compression approx 1 point so 9:1 up to 10:1
 this will definatly help power output & decrease detonation
I always used the "junk" 519 heads with great results , IIRC the 518 is a large port Max Wedge head from 64 & is very rare & valuable

[4406v]

The pictures were not very clear and after calling and asking for the exact numbers they were #516's , I passed on them.