Stop in for a cup of coffee

I am not even building a slant six car but because it was originally a slant six car and still has the K frame, I figured I would install a running slant six and get it running sooner than later. A car that you don't have to push around the yard is way more good times than a dead car.

At this point with this BS, might be easier to swap the K frame out and drop in a 318
Don't let some nonsense on FBBO discourage you!
Is everything else there?
Having done a 6 to 8 swap as my initiation, its a PIA too. well maybe less so if you have a donor sitting right there. I spent many Sat mornings running to the junkyards getting those parts.

If its just the engine brackets, try those p/n and see what comes up. Also try some of the yards and people that specialize in mopars of this era.