I built 1 a couple of years back to test a "profesinally rebuilt" 340 on. I currently am using it as storage for my motor. I did not get around to casters but I have an over head crain to move it with. The frame I built is about 3' wide and 6' long. I built it out of 3" x1/4" angle. I used 2 pieces of 1 1/4 x 1/8 angle as an upright to mount a radiator to. The engine sets on a 3" channel cross Member with small angle sticking up for the motor mounts. I used a junk 904 housing with a strait shift fly wheel. The Transmission case just sits on a 2x4 as I have not needed any thing else in order to run the motor. I have used scaffolding casters in the past as they lock well and can be snapped in place, easly removed and used elseware. I have the casters under my 71 cuda right now to roll it around on.