Really dumb idea to weld it! Why not make a couple of square drive blocks for the gear with the hole drilled in the right position? Then if the pickup coil ever fails, he can disassemble it again to swap parts! Betting his engine's life on a welded oil pump drive is also stupid squared!
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!