Ok, Here's a tool I made for this purpose that I use a lot. You will need at least a 4" Makita Grinder with thin cutoff discs, MIG Welder or something to weld with, a belt sander or bench grinder, PATIENCE! The parts you need is.. go to your local welding shop and get yourself an 8 inch piece of solid 1" round stock.
The Harmonic Balancer hole is about 15/16's so on one end, Sand off a little at a time rotating the part evenly around the sander until it fits in the HB hole smoothly. Make it so its sanded far enough into the stock to bottom out (about 1 inch).
Set your welder really hot so the weld is really good, weld a bead about 1-1/2 inch long in a thin strip.. this is to make the key for that pesky keyway that's on the HB. Weld it high and a little wide so you can grind it down to size.
On the OTHER end of your piece, various things you can do, but I measured, measured again, and so on, and ground a 1-1/2" deep hexagon pattern onto that end to accept a 7/8" long impact socket. This is hard to get right so go slow. Especially with a Makita grinder!
Mine came out nice and I use it but CAUTION! DANGER WILL ROBINSON!! DANGER!! Don't EVER forget to remove it before starting your engine!!
I made it the length I did so it would go into the hole and since the hole is below the radiator I don't have any obstruction.
