Need Help....k-frame

Don't know what part of Alabama you're in. Check with Stephens Performance in Rogersville (Yankee AL to those who live south of Birmingham.) It ought to be cheaper freight if not a good excuse to visit the Rocket museum in Huntsville with a little detour to the west.
Another source is Ron Stitt @ Texas Acres or Dr. Mopar. Google them on the web to find their web sites.

The SB K-frame is a much easier find than the BB. K-frames changed to use spool type engine mounts in 1973, but these will bolt into your car without a problem. I put a 75 K-frame into the 72 Demon with no issues.

If you don't already have one, you'll need an A-body LA driver's side exhaust manifold. The other ones have issues with the steering column. The ones with the big ports for 340 & 360 are pricey. Or you can use headers made for the A-body.