OHC Pontiac streeer, blown Pontiac gasser.
Question, tho: Are you using the stock Healy frames and just saying, "heckwiddit" and let it fly... or... are you swapping a frame/frames?
A neighbor had one stashed in a garage, (think it was a Mk. 2) as a favor to a relative. Eventually, it got painted and re-stashed but was surrounded by coffee cans full of parts, dunno how it was ever going back together. Speculated that it would be a real hoot with a Ford 300 six and a toploader, but one day, it was sold and that was that.