val and val. job??? for the head guys
A lot depends on the previous work. If this 3 angle was done with stones and tapered pilots and the valves truly are stock, I can see at least another 10-15cfm easy through most of the lift range just in replacing the valves with nailhead performance valves. The gains being more from the back cut and narrower stem than anything else. The heads have been ported, so gains from the throat or chamber cuts may be negligable if that was already done. In terms of cutting accuracy and concentricity, and installing oversized valves so the seats can be placed out towards the chamber more, those will add power even if they don't show much on the flow testing. I think what he might see, again dependant on what was already done, is a larger gain in the lower lifts with a slight gain at lifts over .450. I'd say have a modern piece of equipment do the work, install 2.05/1.65 valves in it moving the seats out properly, and stick performance valves into it. A small amount of hand blending might be neded in the throat depending...