i had mine rebuilt thru corvette central
they send u one thats already rebuilt
it s exchange type deal if yours is rebuildable

I'm not speaking from personal experience as I've never rebuilt one,
and I'm currently away from home so I don't have access to info I've
squirreled away for the day I try it, but...

I don't think there's any real trick to rebuilding them, but it's
important to get the end-clearances on the main shaft and the
tach-drive gears correct, to be certain the oil-pump driven gear is
on the mainshaft in the same orientation that it came off (I believe
there are corresponding marks on each), and that everything is
properly lubricated with the correct lubricants during assembly.

Don't try it without a set of detailed instructions.