You are correct, the LS1 is not much heavier then 13b REW.
I must agree 100% Rotary engines are marvels of engineering.
It would be almost impossible to find a 4 rotor, I believe they only made a few for there famous LeMans car.
^+100000, I will always have a soft spot for the FDS3… The little engine that could is what comes to mind first.