"Home-Brewed" modified K Frame with B Body mounts
I'm curious about the engine mounts too. You have them mounted where they almost look even as far as fore/aft.
The stock 67-72 position of the engine mount pads...
Your right side looks close to stock but the left side of yours seems further back. The B body K member below....
.....has the pads almost even which I don't think that I noticed before now.
One quick way to tell an A body K member apart from a B is that the A is flat across the front, the B is curved.