Is there a weld seam along the transmission tunnel? Sounds like your car has had some floor work done in the past
I believe so. I say "believe" because there are two seams both covered in a thick, rubbery caulk like material. I assume it is covering bead welds. One seam runs from side to side behind front seat mounts, the other is vertical along the top of tranny tunnel between front and back seats. So I am guessing they split the back half of a two piece replacement pan for easy installation?
I ain't happy. Matching numbers U code with 46k miles, bought from up north and shipped south. I paid for an inspection as a precaution. Now with what seems to be a piecemeal floor pan and no sequence numbers on cowl or radiator support, my original R/T is looking more like a restored barn find. I do have fender tag and build sheet. It's an enigma. I have about $45k in it and think I have a $28k car.
I found the floor pan issue because I decided to recover the front seats and replace carpet, trying to keep the original look since I had matching drivetrain and build sheet. Now I wonder if its a lost cause.
Floor pan can probably survive with another sheet metal patch and a sand and paint job, but I am not sure what to do. If it is a replacement, and it has already rusted out and been patched once, maybe it was deteriorated when they installed it? I know 44 years is a long time, but how often should a floor pan corrode on a low mileage car?