I'm not exactly sure about your question, but I'll take a shot.
Suntour 7-speed systems used unequal spacing between the centers of the teeth on the cogs. The bottom three are spaced 4.8 mm apart, while the top three are space 5.0 mm apart.
Shimano 7-speed systems are all spaced 5.0 mm apart.
I don't think that your Accushift shifters will reliaby index with a Shimano cassette.