The incredible folding Cuda!

Engine/trans is out. I'll have to check if the floor is level, seems to be... 10 year old concrete.
I don't think I'll be able to get anything 'square' with the mess of the torsion support and frame rails/inner fenders attached. I think it's pulled out the firewall on the drivers side from the weight of the engine/trans on it, and that frame rail being so ratty. The cross member only has a few welds holding on the trans tunnel.
I have the whole front clip to put in. I'll need a whole new floorpan, as it's rotted in the back too.
My question is if that's the right plan I should take.. get all that rusted/twisted stuff out, square it up from the firewall back. Brace it up after I get the back 3/4 of the car square. Get the new (74 dart) front clip in loosely, get a new floorpan, then get it all squared up again before I weld it up. Does that sound like a good plan? Or something I should do in there somewhere?