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It's really no big thing , I thought all old Mechanics knew this stuff , maybe not , who knows ? . when I worked in the Dealer , I read EVERYTHING and paid close attention whenever the old guys wandered over to watch me work on old rigs .
In any case , Generous Motors Corporation knew that light trucks were just tools and so designed them very carefully indeed ~ they'll take a horrible beating and still get you home and always (Chevy) in high style and comfort .
Basically just take the old tranny apart over some BIG light colored beach towels from the Thrift Store and count & bag up the various roller bearings , the counts are REALLY important .
Look closely at the shafts , if you see any wear no matter how slight , scrap 'em .
I used to buy broken & smashed trannies from junkyarsds just to get the good quality parts therin , now you'll have to find an old Bower BCA Bearing Catalog and order up the new rollers and then find N.O.S. or good used gears & shafts on Flea-Bay or maybe from Chevs of The 40's in Wa. State but persevere and you'll be well rewarded with a nice shifting truck that YOU fixed our own self .
Replacing the pilot bushing in the end of the crankshaft and using guide pins (cut off bolts) to re install the tranny are two important details to ensure fully releasing clutch , this makes the shifting easier .
I hope this helps , often Hot Rodders have good take out manual trannies for sale cheaply .
BTW : the opening of spark plug gaps really works out well ~ my current daily driver '69 C/10's 250 CID L6's valve guides are wobbly beyond belief and it was fouling the plugs in 150 miles or so , I opened them up to .050" and added an old HEI dizzy from the junkyard (1977 Nova) and it runs so sweetly it's amazing ~ you can't see the oil smoke but you sure can smell it.....
It hasn't fouled a spark plug since I opened up those gaps , never any miss either .
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