440 swap

So I can weld rb mounts into the saddles of the slant 6 frame? Or will they need to be moved as per the trans requires
If you find a donor a-body big block k member Use it don't cut it up. You'll still have to hack the slant 6 k member. But think about it this way also you get to make sure your k member is nice & strong, nicely detailed & there's also weight savings if you plan on running a deep oil pan & wouldn't have to run an a-body specific milodon.
That's if you can weld well