Glenn forwarded a couple pages of this old catalog for hi-performance parts that included a few for the jeep. He sent these to me after a short discussion with Scott, who races using F-head and L-head motors (more on that to come).
According to Scott, “I have bored them up to .092 oversized and I have had about 6 different cams made by crane cams. The motor I have had the best luck with so far is .060 over with dome style pistons. It has 1.7 ratio roller rockers. It is a F head. I cut the side of the head open and welded the water jackets and built an intake manifold that is 8″ high. With a 500 cfm holley ive been able to get 7000 rpm out of it.”
Scott’s experimentation has been done simultaneous to Sam at Flatfender Willys, who experimented, just for fun, with hi-po parts in a flat head with modern honda fuel injection. Sam did a few other things to the engine, but I don’t precisely remember what. Sam and a friend drove the motor hard, before it finally gave out, though a couple transfer cases and a drive line gave out before the motor did.
Here are the two pages from Glenn.