3B hit the nail on the head.....the end of the crank is tapered so the drill bit centers itself. Most H/B-steering wheel pullers ($10.)are 9/16 fine threads, but you don't need to thread the puller into the 7/16" threads. Put a 1/2" nut up against the threads you cut and use the puller, bolted to the balancer, using the existing factory-threaded holes, to pop the balancer off.
The beauty of taping the crank, which incidently drills and taps like butter, is that it makes the INSTALLATION a snap! No BF hammer and the damage it can cause to the timing cover seal. (I leave my timing cover loose so the seal seats squarely on the H/B.) You simply use a long 7/16 fine thread bolt and the body of the "puller" as a washer and use another 7/16"-fine nut to push the balancer home. The 7/16 taped hole with bolt and large washer will insure that your balancer doesn't "walk off".
While you're at it, tap the front main cap for 3/8 threads so that you can pull the timing cover by removing ALL the bolts from the front of the engine. No need to pull the pan to get at those 2 pesky bottom timing cover bolts. This is a real time saver if you ever need to change out the cover, seal or check out the timing gears. I can now pull the radiator and R&R all the lower end stuff without pulling any sheetmetal.
Hope this helps!
