I remember reading about Koffels creating the B1 engine, they ahd previously played with the Hemis, and according to that article their first B1 mule made 60 hp more than their best NHRA legal PS Hemi. I believe the last Hemi to qualify in NHRA PS was Reid Whistnant, maybe in 1987? When the rules changed I would have thought that Hemi would be The Choice in NHRA PS, but it wasn't competitive. The last one to try was Jeff Wick, he was usually about 0.3 seconds behind Alderman and his N...aturally aspirated B1. Hemi heads have the capability of flowing great, and if head flow is what you are lacking, then it's the key to producing more power. However, it is not so with all out smallish wedge engines. Current wedge heads flow well wnough, and the engines have volumetric efficiences in the 130% range. With that kind of volumetric efficiencies you don't benefit from better flow, other things become more important and the ones that will make the difference. In 1964 things were different, they needed flow and hte Hemi was the answer. Same is still true with "underheaded" engines, (usually very big displacement) engines with limited bore to stroke ratio. That's the only place where naturally aspirated Hemis still have an edge over even a conventional, modern Wedge like the W7,8&9's. If Hemi really were the answer, there would be nothing else.