Stud Sizes for Battery Cable

Anybody happen to know the size of the studs on the starter/block/alternator?

It's raining here, figure someone here might know. If not I'll probably check tomorrow. I'd guess 3/8 or 1/2"?

Think its 13mm,Ray!

Not the nuts, the studs themselves. For purchasing of copper lugs to make new cables.

FWIW, if anyone else does this...

TBI cars have 3/8" studs for everything.

Except in my case, with the Fleetwood 140 amp alt, the alternator stud for the positive cable is 5/16"

How strange. Why, GM? WHY?