[Ross F-1]

Got 'er done! Actually doing it once I had all the pieces in hand, fixture made, etc. took a lot less time than all the hand-wringing! Par for the course...

Gary's excellent drilling fixture inspired me to make one out of square tubing. Worked like a champ. The 27/64" tap drill leaves a little bit of the old thread, but since the 12mmx1.25 is almost exactly 20 TPI, it actually helps keep the tap going in the right way. There is almost no room behind the flange, so I rigged a piece of heavy sheet metal with a magnet to keep from drilling into the oil pan. The tap just barely made it thru to the full-size threaded part.

Thanks for all the help, glad to have this behind me!