Joined: Jan 2008
Posts: 23,639
Likes: 1,106
From: Mans of NC & SW UT Desert
Bikes: 86 Katakura Silk, 87 Prologue X2, 88 Cimarron LE, 1975 Sekai 4000 Professional, 73 Paramount, plus more
Shimano 7 speed freewheels are cheap. So worst comes to worst, you will be installing a replacement RD and a freewheel. I have had marginal success trying to get a pre-indexing Suntour RD to index with Shimano. Its worth a try, but a back up plan should be just installing a different RD and freewheel.