Thanks FYB, mut I checked wiki, and it kinda didn't say, or hinted that it fired HE rounds only, depending on how you take it. But if it did fire AP, and HVAP, that would be a hell of a puch. 105mm HVAP round would take the turret off a tiger.
-1 to the easy 8, lets just get an MW, and a LW variant before we start sticking on all the extra stuff. And if E25280 is correct about the M4 line having the same armor thickness all the way through, then all we need is one tank, and hav 2 gun options for it (the 75mm L40 medium velocity gun, had more powerfull HE rounds as a slower muzzle velocity allowed it to have thinner walls on the shell and pack in more HE, and an option for the 76mm version). It would be a lot simpler to modify the turret (game wise) than build a new tank.