
I welded up my own for my 73 Challenger. (When I first flipped the car on it's side it had to be one of the coolest things I think I ever did in my life). It did the job very well for me basically allowing me to do a bunch of rust repair on frame rails and install frame rail connectors and torque boxes under the car without having to lay on my back getting rust in my eyes. It also made it easy to paint / undercoat the bottom of the car. I purchased some pneumatic swivel casters that did not work all that well. I had to kick them in the direction I wanted to roll the the car. It was kind of a pain but it did the job for me. I have a dirt driveway also and rolled in and out of the garage then back into the garage using my tractor attached to the rotisserie.
I don't think it was very "sturdy" but sturdy enough and it did a great job for me. I think if I put "beefier" casters on it that it would be much easier to roll around. I never had to wheel it up onto a flatbed to take it anywhere but I think it would of made the trip with no issues. I had to borrow my buddy's nice welder to make sure I have nice beefy welds. I only own a littel 115v welder. I guess the good thing is I only had about $400 into it and I can say "I built it" (I know, big deal but it's a big deal to me I guess).
Keep in mind I am a novice at restoring a car.
Below are links to the casters I used and the rotisserie plans with material list. I made the cross beam where the casters attach to 6' long instead of 4' like the plans show. I guess you can keep an eye out for a used one on craigslist or see if someone has one for sale on this forums like FEBO. I know sooner or later mine will be for sale. What I would of done different is where the material list tells you to use 2" I would of went with 2-1/2" and I would use 3" where it calls for 2-1/2" square tubing.
I would feel a little better about having some kind of gusset under the 1' piece round tubing that acts as a spindle where 1/2 the weight of the car is being held up. But then again keep in mind that 4 guys could probably pick up and carry a stripped down e-body. They don't weigh a whole lot.
http://www.mts.net/~hpokrant/Restoration_Tips/1-Rotisserie/Plans.htm
http://www.harborfreight.com/10-inch-pneumatic-swivel-caster-38944.html
Good luck! Whatever you do my feeling is that a rotisserie is worth it's weight in gold.
View attachment 16415View attachment 16416View attachment 16417