Why would one do those things to such an old engine. Mine is a 1970 Ironhead and I am just trying to keep it going. A lot of parts are nolonger available and very few performance stuff. On my bike, the engine casings are no longer available and if they get damaged, I get to throw the engine/bike away.
Personally, I wouldn't do such a thing to an ironhead. If I were to do it, i buy a new engine and then only after extensive other modifications were completed. I'm not an expert but, I don't think the benefits are that substantial, as compared to alot of other modifications you could do.