It is official, rods are toast. Now rebuilders

Probably the difference is in the rear of the crank shaft; there is a hole there where the nose of the torque converter fits in (for an auto trans). It changed to a larger size in the '67/'68 time frame. So you need to stick with the earlier engine. If this is a typical rebuilder, you may end up with later parts on it, just an early crank.

Who/what is this service? There are sadly a number of problematic rebuilders out there.

No need for a stand if you are just swapping engines, just the hoist.