92 camaro. I have the factory frame measurements from a baseline. My question is how to set a baseline so that it is level? I am working on a flat concrete floor. I have the car suspended on blocks by the front frame rails just behind the front bumper impact rail. They are set up to be level side to side. I am trying to set the rear of the car on blocks using the frame rails right in front of the rear bumper impact rail. Again, level side to side. I assume that the body of the car would be sitting level before measuring the frame rails to floor. So, how do you set the front to rear so that the body is level front to rear? Is there somewhere to use a level on the body then measure from the floor to the frame rails? Would I use the top of the rockers at the pinch weld to level the body?

 

I would use the flat concrete floor as the baseline datum and measure up to specific points on the frame, position the body/frame to the baseline using blocking/shims based on those measurements. Add the distance from the floor to the baseline reference datum in the book and use that same correction for all measurements from the floor to the frame measurements points. If you do that, it You won't be able to use a level anywhere on the body/frame, it wouldn't be very accurate and being level is irrelevant anyway. You're looking to set the car position to a reference, which would be the floor. Once you have it set up based on 4 corner points, you'll be able to take the other measurements and see if anything is out of spec. If one of your corner measurements is out, you'll see it show up in the other measurements.

 

Right now I have it blocked in the front under the front frame rails where they connect to the bumper impact bar and I have the rear blocked under the rear frame rails right where they connect to the rear bumper impact bar. The currently front is 7/16 inches higher than it needs to be for taking measurements. So, far it doesn't look like the frame rails are twisted anywhere. I have been out of town for the weekend so will get back to this tomorrow, Monday.