I started with a bench grinder and finished it off with a file. I went back to the vise and filed several tomes to get it to seat completely without getting sloppy. The theory is that you will get complete seating in the oilpump drive, you can use the original hold down clamp (but you'll have to make a bushing out of plastic pipe), and the gear to oilpump distance is the same. So far it is working fine, I still keep an eye on the oil pressure guage, based on the bad experiences of others.
Don't try to use the factory specs on timing. Advance it for better performance and mileage, then shut it off and try to start it. If it bucks when you start, then retard it a tiny amount. When you're happy with the timing, THEN put a light in it and write it down for a reference. Also your advance port will run into the oil filter and limits your ability to advance it, so pay attention to where it is in relation to the filter when you install it, otherwise, you may have to move it back by a tooth.
You will like the result.
Ed Long
Read the article in Tech Links by Jeremy Compton, if you haven't already