How many tubes of RTV should I use...

I watched a crew install a new radiator in an autozone parking lot and then fill it all up with purple power and drive away. We tried to help, they were having nothing to do with us.

Someone probably saw the label said "for water pumps" and so they dumped it into the filler neck.. LOL.
You're right, you can't fix the stupid.
BTW, OP, cool find. I'd love to get my hands on one of those old P bodys with a 3.0L. especially if it's a drop top.