Rebuilt my '90 Sirrus today as a non-triple. 105, 105SC levers, 105 5500 calipers. The seat is slipping, and the review says 27.0 rather than the 26.6 post it came with, so that checks out.

Pleasant riding, only tried hands off once but it seemed okay. I like it. Now I'll have to figure out how much energy I want to put into the beat up paint.