I agree with the Hemi being a "game changer" , like Chrysler or not , the Hemi brought out the 427 sohc , tunnel port and then Boss 429 , with out the Hemi the Hi-riser would have been all they ever needed ....
just wish ford wouldn't have been so "asleep at the wheel" , they could have had a base model 66 fairlane 390 with COAE heads , low riser valves and good exhaust manifolds and run with 396's any day , let alone some 454 tunnel port mustangs with the small combustion chamber and a wide ratio trans on all performance vehicles .... they had everything on the shelf and never pulled the trigger ... woulda shoulda coulda