I think I found them to be a mixture of both metric and SAE on this engine..a bolt is a bolt, but just a royal PITA to keep going back and forth to the tool box to get the right size wrench/socket.
I did make a dolly for the engine cradle out of 2X3 wood for the fore/aft cradle frame, fasten to 2X6 boards running left to right. I mounted 4 heavy duty hard rubber castors on it to move it around. I was concerned at first that the whole assembly might need some sort of brackets to keep the engine from slipping off it, but I found once the weight was lowered onto this cradle, it wasnt going anywhere. It was tall enough that I could put a floor jack under it to raise it up to the cradle to undo the 4 corner bolts then lower all to the ground.
Took several attempts at rigging a chain to the frame to raise the frront end of the van high enough without damaging anything. Used an engine hoist to lift the van then wheeled everything out the side.
Was curious about the engine/bellhousing bolts only because I will need to get longer bolts to fasten engine to engine stand. Have a decent selection of SAE bolts kicking around the garage, but not many metric. Will pull one off then off to hardware store I guess.