First of all I found out that GM doesn't call a duct a duct, they call it a lower radiator shroud! Why lower? Because it has an upper cover.
Anyway, all my dolly work proved to be having only a marginal effect on reshaping the step in the side wall Sheetmetal of my shroud.
Option One was, as mentioned earlier, finding another one and I did call a local dude who has a field of stuff annnd, we are back to COVID again. F****** social distancing means I can't get into his place to do some research and archeology. He said he'd take a peek to see what he had but the only way all this will fly is if I can catch up to him and for all of that I might as well be trying to order a beer in a bar after 11 pm last call 'cause curfew is at midnight.
So on to Option Two; that being the very careful disassembly of the injured sidewall from the shroud. Nothing too complicated, just a bunch of mushroom head pop rivets to cut away; oh yeah, did I happen to mention that those rivets also hold the rubber/fiber gasket in place and any kind of heat anywhere near it will either melt it or set it on fire? So Dremel and I had to be verrr-y careful. Cut a little and then soak the rivet with lots of cold water from the pump gun. Lather, rinse, repeat. 1/2 doz or so rivets later I had one very beaten up panel free and the actual work could commence.
Since the step or shoulder or offset or ?? could not be easily or readily reshaped back to its correct shape, the obvious decision was to cut the dead piece out altogether and replace it. This entailed the services of my Dremel, again, plus a short length of 18 ga body metal that was gathering dust on the drill press table. Process after that was to jig the strip in place using copper plates and clamps and magnets and other implements of mass hysteria and go for some tacks to hold it all together. Gotta love my MIG. Dropped the gauge down to 22 to minimize the heat being put into the metal and bumped the speed a hair and off like a herd of turtles-tack, move-tack, move-tack, move; you get the picture.
Pictures? Maybe of the finished item before I paint it but nothing of the process. My camera stays safely in purdah during anything that involves hammers and heat and dirt and metal shrapnel. Hard enough to get that stuff out of me, never mind delousing my Nikon. It takes enough abuse as it is.
Back at it tomorrow.
Nick