Like Denny, I don't like the idea of driving the harmonic balancer onto the crankshaft with a hammer. It has to be hard on the thrust surface of the #3 main bearing, unless you somehow backup the crankshaft at the flywheel end.
I made up a drill guide for drilling and tapping the crankshaft snout to allow installing the balancer with a threaded puller. Since the O.D. of the drill guide is the same as the hub on the balancer, it can also be used as a guide for installing the timing gear cover.
I decided to use a 7/16-20 thread in the crankshaft, as this leaves an adequate amount of the original 60 degree counterbore in the end of the crankshaft for mounting the crankshaft between centers when re-grinding or checking for runout. A 3/8" thread might be too small for the force required to pull the balancer on, and a 1/2" thread might weaken the crankshaft snout in the area of the timing gear and balancer woodruff key slots. A fine thread is preferable to a coarse thread as it provides more strength and gives more mechanical advantage when pulling the balancer on.
The two photos with the red background show the drill guide, which is machined from aluminum. The hole in the end of the guide accepts three different steel bushings, which are drilled to accomodate a 1/4" pilot drill, a 25/64" tap drill, and a 7/16" hole to guide the tap. The bore of the aluminum guide is sized to a close sliding fit over the snout of the crankshaft.
Prior to drilling/tapping, I bolted the flywheel tightly to the crankshaft to provide a wide base and to keep the crankshaft vertical to the drill press base (and parallel to the drill spindle).
I found the crankshaft to be softer than I expected, so the drilling and tapping was relatively easy. I drilled in about 1-1/2" deep and tapped to the full depth of the hole. If you don't have a drill press, once you have the drill guide and bushings, you could use a hand drill to drill the holes, and they should end up pretty straight. The factory 60 degree counterbore in the crankshaft will center the drill, and the drill guide should keep the drill running straight. While desirable, it's not essential that the tapped hole be perfectly coaxial with the center of the crankshaft.
I used a piece of 7/16-20 all-thread for the puller, with a sleeve to bear on the hub of the balancer. I think a large (1-1/4" or larger) 1/2" drive socket would work as a puller sleeve for installing the balancer. Unfortunately, I didn't photograph the puller installation, but it's a pretty straight forward operation, once you have a tapped hole in the end of the crankshaft. When pushing the balancer onto the crankshaft, you want to be sure your sleeve is pushing on the inner hub of the balancer as opposed to the outer portion so you don't distort or damage the balancer. It takes more force than I expected to get the balancer on. I used a 1/2" pneumatic impact gun to drive it on. I recommend using anti-seize on the crankshaft snout and on the puller screw threads. The threads on my all-thread puller screw were beginning to distort by time the balancer was all the way on, however, the crankshaft threads survived OK. Be sure to screw your puller screw all the way to the bottom of the threads in the crankshaft. It would probably be a good idea to lock a couple nuts together on the end of the puller screw and tighten the puller screw against the bottom of the hole so the puller screw doesn' turn in the crankshaft when pulling the balancer on.
On re-reading this, I see there could be some confusion about the puller screw. You could use a 7/16-20 bolt and drive the balancer onto the crankshaft by screwing the bolt into the threads in the end of the crankshaft, but I used a piece of all-thread as a stud, screwed all the way to the bottom of the threaded hole in the crankshaft, then pulled the balancer on with a 7/16-20 hex nut. Once the balancer is installed, just lock two nuts together on the end of the stud and unscrew it from the crankshaft.
The photos at the following link show the drill guide and the setup for drilling/tapping. I apologize for the poor focus.
http://s1122.photobucket.com/albums/l528/mryeamans/Crankshaft%20Drill%20Guide/Mark Yeamans
VCCA #35724
