How much fundamental difference is there in a Trickflow 240, Indy EZ, Edelbrock RPM head from the factory head?
In architecture? Very little, since they are "stock replacement" heads with standard valve location & angles and standard-offset rockers (not including the MW-port Indy EZs)
In implementation? They each have their own approach to runner design / volume / chamber design / valve sizes
2021 Challenger 6.4L Scat Pack 1320 100% stock: 1.680, 11.894 at 113.75 (DA 175 ft) weight reduction, wheels, tires, Hellcat air box: 1.661, 11.686 at 115.97 (DA 710 ft)
1973 Challenger 452 ci street/strip [2008] pump gas, DOT radials: 1.454, 10.523 at 126.44 (DA 514 ft)
