How much weight can I put on a car rotisserie?

Really, those plans are free now? When I got my set he was selling them for $12, still a hell of a bargain. This is the same rotisserie that I built. FYI, the tubing spec'd for the pivot points on the end frames did not telescope like intended. I forget which one I resized (inner, I think), but it worked fine. You can see the finished unit on my build thread. I would feel safe putting a car the size of an a-body on it with an engine. That thing is a beast. L8r