Mike,
As Jerry stated, this can be a hazard. I did the same thing you are doing simply because the stand didn't readily fit the engine bell housing pattern. I used the holes on the tranny side of the bell housing and still was cautious about the center of gravity being farther out and I was also concerned that the cast housing could break (shear stress).
My engine wasn't frozen, I was at the assembly stage. You are probably going to be applying some working/wrenching pressure on your disassembly. The center of gravity is so far out, that thing could kick out from under you before you know it.
Can you add some weight across the legs close to the vertical support post? Maybe lay some boards across and put the engine head or something heavy on them... just a thought. Be safe!
Jerry W.
