Joined: Feb 2012
Posts: 19,362
Likes: 5,503
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
The OP says an old Shogun, how old? he says Shimano 600, which version/part #?
If the bike/gear system is pre index (which for 600 would be about 1986 IIRC) then the rear der and, if still OEM, the cog set and rings. I don't remember reading of some one who has mounted current indexed shifters with that vintage of 600 and reported their results. Quite possibly a few shifts would be fine but after that the build up of incompatibilities could be problematic. I would expect more issue with the ft der, but too few people talk about that aspect of compatibility. Andy.