Here's something to consider RTV silicone in not for use with gasoline.
I did this about 45 years ago on a ford just like what your working on and I used RTV to seal it and while it seems to work at the time it was my daily driver PU.
Then one day I was driving along the road and it started to run like a POS cause the RTV swelled up and cracked the spacer plate leaving me stuck on the side of the road a few months later.
Even if you draw file the carb flange then put some good epoxy on the surface to fill the eroded area then draw file it flat and use the soft pliable carb gasket like the MR Gasket ones and double gasket both sides of the spacer as I did that will solve the leak.