Looks good. ... anything B1 related is going to require a lot of hand finish work. Having access to a mill allows you to do a nice professional job rather than hacking things up with a die grinder.
I am better with the Bridgeport and lathe than the hand grinder... LOL
But I think this pushrod clearancing can easily be done by a professional head porter with a die grinder and carbide bit.
Since I am making clearance for using either lifters with centered pushrod seats and offset seats, the Bridgeport and long endmill does make a nice straight, long passage for the intake holes.
If using typical lifters with centered pushrod seats, the existing holes need very little work at the bottom, more at the rocker end.
