Different story on the LP heads Bill, as you already know.

.100"_____64.3
.200"____123.7
.300"____177.6
.400"____228.9
.500"____271.3
.600"____285.8
.550"____294.0
.650"____298.6
.700"____300.8

2.02" x 30º BC

These SP heads won't even compare as-is. The
pushrod pinch is really the only difference.

The rest of the port just puts too much demand on
that diverging wall.