Great Project!! I had a 73 340 duster years ago. Was a good car. Not sure how you plan to drive it, but mine was REAL light on the front end at about 120+ mph. Definitely needed a front spoiler or...
The battery was in the trunk. Rear leaf springs had original main leaf with the rest of the spring stack from a 68 R/T. Straight line accel left two equal length black tracks even without a locking diff.