I was able to final fit the firewall (more trimming), and with a calm day I managed to mig it in place. The rear of the assembly was gas welded with an 00 tip. One blow through with the mig on the rear and I would have had hours of repair.
The mig leaves a lot more metal to grind but even less heat than a tig. NO blow through with 2" stitch welds. After grinding and a little sander work it is suitable for the media blaster. The front floor and tunnel with a flange is in and ready for the 1/4-20 square nuts to be welded in place. The entire front floor is removable with eleven 1/4" screws.
I am glad I didn't bid this job, would have been working for peanuts!
The rear floor has been frustrating due to the fact that I was unable to get it rolled at a sheet metal shop. They simply did not want to do the job. They took my precut/drilled sheet and then lost the template and a second sheet that needed to be broken up for the rear inner drip rail. Do I know how to pick'em???
My neighbor is a retired sheet metal man and offered to take me to a shop that he knew where we could use a roll.
The shop was very well equipped, clean, and the power roll was very new. It took 20 minutes to double roll my scribed sheet. Very nice..
I had a scribed strip for the rear drip rail and we broke that up at the same time. In and out in 45 minutes and the floor fit the subrails nicely. I also got a quick lesson on " true lines" which I understand completely now.
The floor is mounted with six screws for mock-up and will be welded in place after the body is bolted back on the frame. I have about 16' of randomly applied stitch welds and maybe 60 or so rosette welds ahead. I'm going to be beat after rolling around in this car while alternately stiching the floor in place from side to side.
This is the "as sheared" 16 ga. front floor and a prefab tunnel from Howell sheet metal in Texas. The tunnel has a slight twist in it as stamped (easily removed) and is very nice.
The floor must now be trimmed and fitted to the firewall that is clamped in position.
Now trimmed around the edges and fitted to the firewall it looks pretty good.
The transmission relief required several final adjustments even with a cardboard template. The hole on the driver side is an access to the master cylinder lid. I turned a 1" edge to the rear on the firewall that accepts the front of the floor.
Using the section of floor that was removed from the center, I scribed the angle on the tunnel and carefully cut it for the firewall. In this installation, the full length of the tunnel ( 17" ) was required.
I am pleased with the mockup, it looks clean and smooth. The original concept was to weld the floor in place but I think with the addition of a flange on the front of the tunnel, I can make the whole floor removeable. This is going to be nice.
