That's the thing though, the suspension on there is worn out. Bushings are blown out and it won't give me a positive variable to work off of. I mean, I may be splitting hairs on making this issue, but I'm a perfectionist when it comes to doing things. I could go by where the rims are I guess when it's finished. Measuring when everything is put together and making sure the spacing is correct in the wheel wells. But then I have to make sure the motor/trans is straight too (have new motor mounts and trans mount to install). I have to make sure the driveshaft is straight to the carrier, and from the carrier to the rear end. There are so many variables here that it makes my head hurt thinking about it.
The frames (front and back) were pulled from a 300 that didn't have a wreck, so I know they haven't been tweeked at all. They were in good shape. I'm guessing I'll have to pull out the tape measure and make my own "squareness" and hope for the best on the alignment. Initially when I started this project, I didn't figure in that the assembly could be shifted, but when cleaning out the frames on the car for rust, I noticed that the bolts for the frames could be shifted, which brought on this question.
I would replace only one thing at a time.
Motor mounts.
Trans mount.
Drive shaft.
Carrier.
Before removing the old cradle,
I would measure where the old bushing had been in relation to a subframe point on each side, and if possible, another point front to rear.
That triangulates where the pivot point had been.
Then replace the rubber bushing....see if where I presumed it was is where the new bushing center is.
I would measure where the rubber bushing had been, to determine where the center is or will be with new bushings.
NAPA, machine shops, speed shops, race car shops, etc. can press bushings in with a hydraulic press
A good starting point is to get equal distances on each side.
If you already removed something, with new bushings, you can re-assemble
it and get bushing distances the same per side.....as a starting point.
You will need a new alignment anyway so get the distances the same per side, before you take it to alignment...if you did not measure in advance.