Just one more comment/question. Where, and for what engine are these heads available? As for as I know, unlike the Ardun conversion in the 1940's, which was an overhead conversion, not actually moving the valve train, and cams, to the head, you just don't buy a kit, and put them on the most popular engine, currently in use in Sprint cars, there would be a lot of expense involved, including a lot of machine work to the engine block, to make this conversion. Don't think so! Bob