67/68/69 cuda dilemma
My plan was to leave it semi boxed in instead of just flat strapping it in like most of these are done. Doing most of this from inside the car with no floor pan installed is for sure the cats meow.
I feel leaving it semi boxed helps keep more of the strength than just cutting it all completely out and flat strapping it. The OD unit is pretty straight and isnt wider at the front where the crossmember mod is. This is one of the reasons I am leaving it semi boxed, plus it's easier to fabricate the strap that way. The drawing shown, the blue is the original crossmember, red is the added piece, the orange is the floor pan angle.
The bolt in crossmember will be made of 11 gage sheet steel, and be bolted with 4 bolts to the torsion bar crossmember. This should all be plenty strong.