This post will be a little long. My Brother has a 2020 Challenger 1320. It's almost completely stock. It' has bigger injectors, smaller crank pulley and tuned for E85. It weighs 4330 lbs with him in it. In good air it has been 11.00 in the 1/4 mile. That comes up to 638 hp on the Wallace power calculator. Now to my point. How much HP can the 6.4 Hemi block take? I'm thinking with some compression, a solid roller cam and a good port job it'll make 700 plus hp. I know that the rods are the weak point. What I'd like to know is will the Hemi mate to my SBM trans and converter. What is the high point that the block and crank will take? I'm thinking about selling my SBM stuff and going Gen III when my current Bloomer headed engine is due for replacement.