Father-Son 1974 Duster Project

Well after getting into our new place ( not the one with the big barn.....long story, we are working on the project.
Pulled the existing 318 and found the 904 housing was mangled where the starter mounts. Told by a professional mopar mechanic this is not repairable!

Also discovered that there is a socket on my k frame that holds a suspension arm that has broken loose, the same mechanic has advised me it's safe to weld/repair and he suggests i find a replacement k frame.

And to top it all, the 360 I bought from a Preacher in Vermont who touted the motor as a " great driver " had rust in 2 of the cylinders and the same mechanic who advised me on the other damage said it couldn't be honed, and I'm not sending to a machine shop.....

So I'm in the market for a running 318 and a 904 at bargain basement prices. And I need advice on the K Frame repair