Wedge something between the crank and the engine stand, so when you drive the balancer on, all the force is not applied to the thrust bearing. Standing the engine on end with the crank on the ground is best, but pretty unhandy! Heating balancers to 200* is OK and will greatly help, but you need to work fast. Dry ice on the crank snout also works, but again, work fast. Once it stops, and you are not sure if it's right, it may be best to pull it off and start again. It could gall together and never move if you keep trying. Cranks are easy to drill and tap, I have done a few with simple hand tools. Being dead center is not that important, being straight is. I used a small block Chevrolet bolt and washer and pulling it on with a bolt was much easier.
