Anyone know what the proper thread size is for the primary gear end of the crankshaft on my 74 DT360? Id like to chase the threads with a die as they are messed up.

For anyone that comes across this the answer was M18x1.0 RH thread, I picked up a thread cutting die from amazon for $13 and now the crank is sorted!

Good one. I thought its probably the same as the sprocket nut but might be wrong. Talking mag side nuts for a minute, at work often we'd get a motor where someone had tried & failed to get the flywheel off & hammered the shaft so stuffed the thread. We had a set of adjustable dies, so i'd back the jaws out & go past the damage the adjust them up & wind it back off to sort it.