I think Bill is probably a race car genius. It sounds like he did a nice job with the stock size valves. I may be tempted to skip the larger valves for fear of hitting the watter jacket when he enlarges the valve bowl.

Regarding pushroods and lifters. The stock pushrods are adequate if you don't put on big valve springs. If you stay with an upgraded stock diameter single coil spring they will probably be fine, but of course that dictate factory lifters.

I have had occasional problems with the stock lifters not rotating and failing. I have also had issues with pitting and chipping of the surface hardening on the face. This is partially rpm related. Some of them have almost no convexity to the face. When you have them refaced John can add a little crown to the face. I have a set of refaced lifters in my ITB car currently but they have only been there for a few races so my experience is a little limited. So far so good. It does seem the chevy lifters and tube pushrods are a proven setup and that is what I use in my production car.