yes, short the NSS or tie it to ground and see if it starts, that's only a start safety, not a "no go' tranny issue. The mounts you need for a LA (318) in a 6 in a 64 are just generic any year 318 brackets . The K is not different, both 6 and 8 motor mounts end up in the exact same location/hole. Trans pan is an easy fix, just crack the pan open, catch all the fluid (that is left) and remove it. scrape the cork gasket off the trans and pan and install a new one. Torque the pan down in a star pattern to 150 inch/lbs and refill. lay under there and watch it. If you see a leak, wipe above it with a paper towel and see if its coming from higher than the pan, that would be a sector shaft seal, a filler tube leak or a cable leak, oor even a possible speedo cable leak.
