Ill have to post up a pic of my afternoon Dolly project. I made mine so it could bolt up a tranny too, 6 casters and the ability to bolt it up and remove the pan. I plan on using 2" swivel casters @ 150lbs for a 900 lb load rating. Well see if it holds up. Mine HAS to bolt to motor mounts as that is what ties the side supports in. I got a glass smooth concrete slab floor, $24 in casters and $14 in metal.