I have a set of 1970 heads that have Stage 1 valves in them. Is there any way to tell if these were originally stage 1 heads or if someone before me put the bigger valves in? Looking in the bowl area I can't see any machining marks that would indicate opening them up. Thanks
Mark This isn't gospel, but the factory stage valves that I've seen all had the "dip" in the face with the 3/8" edge (like in the photo below). Also, most stage 1 aftermarket valves are stainless, which means a magnet won't stick to it. I'm not saying that this is the fool proof way to verify, but all the original stage valves that I've seen look like the one in the picture.
There is NO way to tell. The factory took the standard head & machined it out. Anyone can do that. If you have the original valves, I suspect they are JUNK by now anyway. I had a set of originals, and sent them to the dump & replaced them with new stainless. I did the same with the pistons, rings, bearings........:sleep:
