This is from my 72 factory service manual.  Should be the same.

Not sure what A.I.M is lol did a search and came up with nothing. can you enlighten me. thank you

This is the diagram I have. Perhaps Im getting in to the weeds? was thinking some thinking that measured out control arm mounting points compared to each other and trailing arm mounting points to ensure everything is where it belongs. but thank you!

The AIM is the factory work instructions on building the car.

I think if you measured the dimensions in the diagram and check the squareness of the frame by measuring diagonally to the body mounting points then you should have a pretty good idea of how straight the frame is.

1973 L-82 4 spd

SORRY my Friend.  "A" assembly, "I" instruction  "M" manual.  It has a multitude of information on getting your ride in correct shape. It does NOT tell you the sequence in which it is put together. 

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Thank you, Gentlemen. I now know the frame is 1/2" to 1 " out of square. seems to be damaged just behind the driver's motor mount down to where it straightens out for the rockers. Its sad this is a number matching car, Frame, engine, and Birdcage all still together, trans and diff are marked correctly for the date. Not sure what to do, straighten the frame is beyond my ability. if it wasn't numbers matching, I would just get another frame, but I hate to do that on this. Any Ideas???? would even consider swapping project with some one more capable and wants numbers matching car. Suggestions welcome and thank you !

Since it sounds like you're down to a bare frame, I would think a body shop that has frame straightening capability could do that. Not sure how much it would cost however.

I guess you could  weigh the cost of straightening it versus the cost of a replacement frame.

1973 L-82 4 spd

My opinion, "I" would go the route of having a Professional look at it, and let them do the fine tuning. Not sure, but a half inch may not make a big difference. The alignment shop may be able to compensate for it once you get it all together. Are there stress marks where it possibly could be bent? 

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Where do you live?

I live In Dover Tennessee about an hour northwest of Nashville.

If you put that in your profile, the rest of us can see it and maybe have a recommendation.