mounting options??? help

You have 6 bolt holes the transmission bolted to. The stand's upper arms bolt to the uppermost two holes and the other two arms bolt to the lowermost two. I usually bolt the arm assembly on while the engine is swinging from the lift. Then I slide the rest of the stand on and lower the whole thing to the floor. A lot easier to put the stand onto the engine than the engine onto the stand.
Incidentally, before you tighten the brackets all up to the back of the engine, position the stand's center pivot "up" close as you can to the big steel "freeze plug" that covers the back of the cam. This will postion the engine close to center balance so you can turn the engine upside down without it trying to flop on over. With heads still on the engine will still be a bit topheavy but the higher the pivot is the easier it will be to control.