Where to start?

DentalDart said
I was thinking add torsion bars and suspension, fuel system, brake lines/brake system, and everything underneath the car. Then add floor shifter components. Start working on interior after that while car is waiting for final paint?

I was going to suggest like others above, brakes and suspension. Get the car ready for that big block.

I'd have that Dana 60 checked out before I stuck it in anything. It took a hard hit.