I would think that the camshaft spacers might slip during this process.Then you would have to try to get them realigned or they may fall to the oil pan. He really needs to see inside if the block around the pin is badly cracked.
yeah paul, the camshaft end spacer would be a concern if your not familiar with where it is.....
probably better to remove the sump and check out the back of the block in that area, too.
you could use the magnum until you get the k going again. thats if it lasts. you did say it had a knock and that is a concern. depending on where the knock is, you could stick a hole in that engine before you get much use out of it. if it were me i would be checking out that engine internally before using it. a bit of time spent here could save the engine.
if you can do without the tractor, i would work on the k engine first. if you are lucky it might be a quick fix, you dont really know for sure until you get into it.
i would probably get the magnum as well, but i would work out whats causing it to knock before using it.