Kit, concerning the rear band, spiral wrapped is about the best way I think to describe it. It may also be some wider, not sure though as I haven't compared it against a single wrap. Because it's double wrapped it takes more movement to compress it thus the reason for the different adjustment. I haven't worked on enough 904's to know what all yrs. they were used but they were used for a while and I believe they can be used in any 904 (someone correct me if I'm wrong there). There is only one lever ratio for the rear band so there is only 2 adjustments, 1 for the single wrap band and 1 for the double wrap. The front band is a "shifting band" so the factory used different ratio levers to suit there desire to have it shift how they wanted (firmness). The rear band is not a shifting band so it would make no difference on what ratio apply lever it used. Here's a picture of a double wrap band