I am about to repair or replace the floor pan in my Super Bee. I have a couple choices. 1)patch the existing pan with metal from a parts car with good sections that I need. 2)replace with AMD floor pan. 3)pull floor pan from parts car and patch the holes in it and install in my car. I realize a ton of work either way. But let me get to the question...
If replacing the whole pan, would the car (hardtop, no sub frame issues.) need to be braced in some way? Will removing the whole pan cause any structural issues putting it back in?
I also had the thought of welding the US Cartool frame connectors to the subframes before removing the pan if I go that route. Thoughts?
Thanks.

Next to gas pedal and console

Next to front mount on seat track.

Obviously the drain hole.

Next to wire track.

Ive done a whole pan.

I set the car on jack stands supported by the frame rails (pull tires and wheels and just let the suspension hang ) then carefully measure the distance from frame rails to floor ( was sitting on smooth and level concrete btw ) And cut some 3 " square stock tubing and tack welded to the frame to the floor to prevent ANY sag once the entire floor was cut out.
And replace the pan with one piece.

Might be overkill, But Im of the mind better safe than sorry

I might weld the subframe connectors in, without attaching them to the floor, then cut the old one out.
Thanks for the reply.

I think I would wait on welding the frame connectors in, until the new pan was welded in place. If there is a slight difference in the old pan and the new AMD pan....it would be a pain in the butt to weld the new pan in if it was a fraction deeper than the original.

I agree. I had to scribe my US Cartool frame connectors to the floor plan in some locations for a nice fit so I think you are better off scribing to the new installed floor plan.

Be advised, the toughest part of that whole job, (IMO) is the weld where the pan meets the firewall, especially the corners of the foot well. If I were doing patches I'd consider removing them from a donor car, but if going the whole floor, I'd start with a new, whole pan. It might go without saying, but I would not attempt to do the whole pan unless I had the engine and trans out, to make accessing the firewall to floor pan seam easier. Making frame connectors from 1 3/4" roll bar tubing would also work, and you could get them tacked in place before removing the floor, insuring the car stays square. and then finish welding and painting while the floor is out.

Good thinking, guys. I hadn't thought of that.

More food for thought. I am thinking about patching with a good pan from a donor car I have, but I also have a full floor pan. I guess I have some thinking to do.

As for the frame connectors, on my '64 I used 2x2 and cut a window in the rear rails.
Drilled a couple holes in the sides of those rails.
Slid the 2x2 into the rear rails,
Welded the perimeter & at holes.
Used the usual plate at the front.
On that car, part of the rear footwells touched the 2x2 but wasn't an issue.
If you do that method, you'll know about any interference before replacing the floor.
Obviously, they stiffen the structure while floor is out.
I've heard that the connectors that weld along the floors create a problem with the E-brake cable, but a tube for the cable would solve that.

I have the connectors already, I've had them for a couple years. Lol. They definitely interfere with the e-brake cable, so that's another hurdle I have to overcome.

I replaced the full floor in my 70 Charger a few yrs ago and also added the USCartool frame connectors. I did not add any bracing to the car when I cut out the floor. The engine, trans, and rear end were out of the car. I leveled the car up on about 6 or 8 jacks stands and wood blocks. I left the doors on the car so I could check to make sure the car wasn't flexing by opening and closing the doors. My frame rails were solid, but if yours are rusty at all, I'd weld in some temporary braces. I added the frame connectors after the floor was in, and it did require some minor grinding to get it to fit flush to the floor. If that's the connectors you are using, I would definitely install after the new floor pan.

What I did for the e-brake cable was mark the routing of the cable then mocked up the connector to the floor. I figured out the angle and height that the cable would need to go straight through the connector. I then ran a piece of tubing through the frame connector at an angle, welded it in and ground it smooth. It came out pretty well I think. Unfortunately the car still isn't finished though...

Rich