Fastest/ most powerful slant six?
The slant six powered "door slammers" That I know of in the 9's For the 1/4 mile. Can't give exact ET's as I don't remember. There could be others I don't know about.
Charles Myers Plymouth Arrow. Methanol/nitrous
Dale Rose Plymouth Arrow. Procharged/?
Leighton and Tom Drake 1938 Simca. Turbo/methanol
Cox Bros 66 Dart. Methanol/nitrous
Will Burns 67 Cuda. Turbo/?