Smitty says:I was fortunate to have one of Mr Horning's heads in the early 50s. It was a fabulous (and insanely expensive) way to make a Stovebolt fly. It had pretty much the same effect on an early Chevy engine as running 20 lbs boost on a Corvair engine. It made a pretty good bottle rocket out of the lower end because it allowed it to rev out of sight.