73 mm BB in a 68 mm BB shell?
I've been looking for a 113 mm BB cartridge to try to match my SR Apex chainset to a 1984 Trek 610 (C&V bike content!), and the local co-op gifted me with a very smooth UN73 with the right threading and spindle length. The BB length however is designed for a 73 mm shell - it's even marked on the label and I didn't see it. I haven't tried to install it yet to verify but I've had the problem in the past.
I think I only need a non-drive side cup salvaged from a worn 68 mm Shimano BB cartridge.
Any better ideas about a "minimum fix?"
Anybody have one of those to spare?