The grease helix in a home-brewed bushing can be cut freehand with a ball-end carbide burr in a die grinder or even a Dremel tool. It doesn't have to be perfect unless you're as anal as some of the guys on the forum who would have a coronary if something hand-fitted without a GM part number was ever found on their trucks.

Edit: There are several complete sets of adjustable reamers on Ebay right now, with extended shanks and centering cones- - - -exactly what's needed to line-ream the spindle bores for oversized bushings. Some of them are CHEAP! Search for "expandable reamer". There are several pages to check out, and I just counted at least 5 sets with extended shanks.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!