Does anyone here have know if the frame dimensions changed from 68-72?

I have a 72 Cutlass S I'm working on, and even though the frame and body appear straight (frame measures straight when checking all diagonals) The vertical dimension aren't jiving with what I can find... My frame measures almost 1/2" different when looking at it from the side, the rear most mounts, and radiator support mounts measure closer to the ground than the drawings show.

 

They should all be the same 68-72. There would be some differences with boxing for convertibles, but the mounting points should be in the same locations.

 

Frame chart dimensions (unless noted otherwise) are for measuring the car assembled. A frame by itself may not measure out to spec. Also frames of that time could be as much as a quarter of an inch (sometimes more) off from perfect. My questions are, #1 do the body panels fit good? #2 Are there any marks on the frame from previous straitening? I've seen many straitened frames with the ends pulled down too far. It's a very common mistake on A body frames.
Last year I was showing a customer four frames that were at my shop. We put a tape measure on all of them and by just measuring from the body mount holes, I was able to show that none of the frames measured exactly the same and that one that had never been hit was a quarter of an inch longer on one side than the other. ~BOB

 

No evidence the car has ever been hit, or the frame straightened. I was going to box it, and thought I should measure first to make sure I don't screw it up. Thats when I noticed the dimensions I found didn't line up with the frame I have.

Thanks for the insight

 

I took my rolling frame to a shop. They put it on the rack and said it was within specs. He did not mention that the body was not on. From what he told me they all measure a little different but you usually make it up by adjusting the body panels. I don't know what the amount it can be out before it is considered bent or out of spec.

 

I have mine at a body shop right now having the left front frame horn pulled from old collision damage. First, I had a heck if a time finding anybody who was even willing to do it. They said that the specs on these cars were so often wrong or incomplete that they don't even like working on them New car specs today are often within 1 millimeter while the older cars ( as mentioned above) are often at 1/4 inch tolerance. I finally found a shop willing to do the job and I'm supposed to get it back tomorrow. I have the complete front end off and driveline out if the car so it was easy to work on but from talking to the guy on the phone, it's pretty clear they regret taking on the project. It's not that it was bad, it's just that they ran into exactly the kind of issues described here in getting it right