Low Comp Head Choice

I used 906s on mine when I did this. Hardened seats, bigger valves. Cost me $550 with my castings.

On my 440 I used 516s with bigger valves, practically the same as above, just closed chamber. I added 4 degrees advance on my cam for more mechanical compression.

My choice again would be to match port as much as possible, 4 degrees advance and 516/915 heads with big valves. Still $550 at my shop.