Just a couple of comments. They are both great. My Challenger has an EFI 496 B engine and I'm on my 3'rd DD hemi. I see what the "built" gen III hemi's can do and its impressive.

They are quite different though. A big wedge has "effortless" mid range torque and the Hemi likes to spin. Different experience. The Hemi needs more gears than the wedge. A 727 is OK behind a wedge but would not work well behind a Hemi.

Also the fuel system with EFI needs attention and improvement. With no carb bowl to cover momentary gaps in fuel delivery the system needs to be bulletproof. A sump or baffled tank with pump in tank is needed.

Whichever you pick, have fun!