Hi Bob
First we are talking Chevy CMP?
Assuming yes then, as to which way you drive out the lower counter shaft I'm not sure which way it likes to be driven, put it is definitely one way. I believe the end toward the bell-housing is tapered so that it goes in from the rear and is driven out toward the rear.
Someone please confirm, because memory says that someone on MLU has BROKEN a case by driving the shaft the wrong way. (15 minutes later checked the manual and the lower
idler shaft goes in from the rear and out toward the rear, my problem was what the different shafts are called.)
Strange you should be looking for transmission parts it is the Second Transmission Rebuild Question This Month I've read. Herman, in Belgium was in touch last week looking for help with getting parts to rebuild the lower cluster shaft bearings for his CMP. His problem was his e-mail would not work to get in touch with Obsolete Chevy in Georgia little e-mail relaying e-mails between the gal who knows what parts they have stashed away, and Herman and his parts are now on the way.
Obsolete Chevy
http://www.obschevy.com/Pages/OurCatalogs.html parts is where I've been getting transmission parts for years. They are the ones who had a NOS transmission when I needed on two years ago. You can check on line to see if they have the part you need. But if they don't have it listed give them a call because they have a lot of parts not listed in online catalog because they have only one or two.
Cheers Phil