We leave that to the Leineweber's. I see Jim is trying to keep the business in-the-family and continue the traditions of quality products - and performance !
The guy I have do this for me uses a Bridgeport Mill with the head indicated in on the table, cylinder head facing up. This other method (above on a lathe) works too, but may requires more fixtures, and that weight spinning around might be a bit more dangerous !
Indicating and Measuring:
Here's a photo (from Lee Wickstrom) indicating in a cam bushing(or needle bearing) hole for boring. When this area gets cracked (common on early bushing motors) and welded - it tends to warp. It's very subtle - not much. But when you go to install your cam and it binds, and you've measured your pinion gear mesh . . . and all your figures seem correct - you'll be scratching your head. WTF? Reaming or matching to your gear cover bushing will be in order. Nothing worse than a binding cam.