I've done the same with my old Cannondale, going to 9sp from 7. One thing to note with the old chains, the chainpins stuck out a bit and the chainring caught that and the sideplates on the upshift. with the smooth sideplates on hg chains upshifts are mediocre at best on old chainrings. i finally went to a new 9sp pinned and ramped big chainring.