I've been taking apart my 1964 Chevelle SS to clean up the frame and do a nice resto. I'm at the point right before taking the body off and something occured to me. I never had the frame checked for being out of sync. I know someone lifted the car wrong somewhere in its life because the bottom rail of frame is bent upwards below where the drivers side door is. My question is Do I need to leave the body on to keep the stress levels equal enough to be able to measure? Should I even be worrying about this at all? The cars only been in one wreck in the rear end and quarter panel was simply fixed. The front end is almost gone except for the suspension and wheels, no engine or tranny but still towable or I could put in on a trailer. I probably should have thought about this earlier in the resto (like when i still had it running)

I would think that a bare frame sitting on three not four jack stands would be the best way to measure it. That way it will "find" it's relaxed state. I wouldn't want the body to be straightening the frame. From that point you must level the two jack stand end and then check the other end for level. That should give you the twist in it. Then you must measure corner to corner to see if it's racked. There are holes in the frame for this but I don't know which ones in particular. My frame is bend up under the door from improper jacking too. I'll fix when I "box" it.

I am in the process of rebuilding a 70ss. I was about to replace my rear quarters. The rear cross member was used to pull the car, and was bent way out, plus the car had been hit in front of the drivers door. The body man I have been talking with suggested I have the frame checked, before installing the quarters. I took the car whole to a frame shop. They checked and sure enough the frame was out of square. He stated I would not have got the body parts to fit well and the car would have dogged legged. It was the best way to be sure the car is straight and square. Now all the body parts have good reveal and the doors and front quarters and the hood all fit with a good 1/8 reveal all around. I would recommend doing this before detailing the frame, I went about it wrong, did the frame then took it in. Now I have a lot of paint touch up to do. Hope this helps.