I vaguely remember someone (Billman?) once stating that the drain and fill bolts on the diff are the same thread?

I'd like to get a pair and drill them for a safety wire before heading back to the track next month.

 

yes they are, I once installed the drain bolt on the fill side by accident. I later bought a second drain bolt and ran it on the fill side permanently as it was magnetized, so two magnets better able to to trap more metal particulate. Same threads, the heads ae just different sizes, 23 mm for fill and 24 mm for drain but they fit in either hole.

 

Thank you. The heads are kinda thin, I hope I can drill them out for safety wire w/o ruining them.

I could always buy the J's Racing ones which are already pre-drilled for $50 / .

 

I've always wondered what the reason is for the two different head sizes. It is annoying.

 

Probably so people don't mix them up and the magnetic bolt goes on the bottom. It never bothered me as I would use a long 23 mm box end wrench on he fill bolt, and a 24 mm socket on the drain bolt with a torque wrench to tighten it to spec. You wouldn't use a box end wrench to work on the drain bolt, and I could never fit a socket on the fill bolt.

 

Does the fill bolt magnet pick up anything?