"...Wondering why nobody says... Wow great idea. Get some old high comp small valve heads for practically nothing cause nobody wants them, spend $750 at the machine shop, throw them on and rip it up? My experience is that if nobody says that there is a very good reason. What reason?
I've done it to a set of #47 heads. And will be doing a set of small valve #16 heads. It's an expensive hobby and there's no way around it. Come to think of it everything in life is expensive. If your going to rebuild any set of heads with new valves,springs,keepers...etc price is going to be close if it's a big valve head or small valve head. Cost difference between valves is minimal. Installing screw in studs isn't a deal breaker $100- $180 depending on what the machine shops labor rate is. So if the final cost to do all this is around $800- $1000 is that terrible? I don't think so. And especially if all is done correctly you have a set of heads that will last another 40 years.