Bad head for my 512 stroker
My machinist is trying the seat replacement first.
The 3462346 castings came in two sizes, 79.5cc & 81.5cc, however you can reduce the volume even more with flat valves rather than tulip but with a weight penalty. My reference to "small chamber" may have been misleading. Nothing compares to the 2708915 @ 73.5cc.
Thanks for the comments.