JimB having success with an old tranny was not an endorsement.
Sorry if I wasn't clear but I would NOT recommend anything pre 85 for serious shifting. Early 5 spds are G28/01 to 09, and all are about equally bad, but I kind of assume some things were improved over time. I have a G28/08 in my 83, and I don't know how many models it applies to, but the input bearing that should be replaced with any "real" rebuild is $500, some years its like $60.