Stovebolter Jorb did a great job documenting his Okie busing install and you can clearly see the internal lubrication grooves
here. In contrast the ID of a factory type bushing looks like
this. This is why I hunted down NOS bushings even though I'm surrounded by machine tools every day and would venture to guess you could put twice as many miles on the factory style bushings over an Okie replacement. They're out there if you look for them...an old transmission shop near me had NOS bushings in his parts stash.
