[ken-r-mer]

My understanding FOR MODIFICATION OF THE ALUMINUM HEADS
1) Get the head surface milled

For just the piston dome:
1) Measure each cylinder piston maximum height above the block deck
2) Measure each piston dome center depth of the head
3) Take into account the selected compressed head gasket thickness
4) Have each dome cut to get a 0.040" quench height matching the piston top radius shape (+0.40" added to the piston radius) for the custom cutter shape.

Then for the overhead valve clearance:
1) Measure the high point of the angled valves in it's seated position above the deck surface (all 8 pair sets of valves)
2) Using the selected Schneider P-3/8 cam grind with a max 0.365" lift
3) Weiand stock heads with a head volume of 69 cc, 0.425" max. lift exhaust and 0.455" max. lift intake (Joe Abbins tables 4-2 and 4-3). Followed by a depth gauge measure of each 2 points of the valve areas of each piston for verification and accuracy.
4) Then there is whatever the milling thickness is to clean up the head surface.
5) What is the minimum valve clearance between the valve and the upper head surface measured at the valve back side (highest point) recommendation?

The interpolated combustion ratio using Abbins table 4-1 has my ratio at 7.3-7.4. So on the high side of 87 octane and will probably safely run 91 octane.

Oh and in researching Ross Flathead pistons: in a supercharged setup, the fine print limits the boost to 5 psi. So I'd have to get a smaller pulley to reduce the psi from 6-7 to 5.