Sending the cores will leave me with 2 AMXs that don't roll. I can't be doing that untill I know I'll be able to get them rollable again soon.
I'm thinking that you are going to have to have either a chassis or make a jig to simulate the frame rails, and have the crossmember bolted to it as you cut & weld the drop-out center section.
I may have the frame measurements in my '71 AMC factory shop manual, I will have to look.
I have a complete set of the '71 AMC fische cards if you need any part numbers or exploded diagrams for any other purpose. I'm thinking I should be able to make adjustments to my digital cam in order for the fische image to be visible.
I will be getting an '04 Mopar Performance catalog as soon as possible, I will post relevant (to us) part numbers and prices then.