Oh I'm so glad I read this. . . do not put 5 clutch plates in the high gear drum without being very careful. Yes it works but there is a potential for a big problem there. The problem is that the input shaft/rear clutch drum splines do not engage the bottom (5th) clutch. I had one that I went round and round on trying to figure out why it would only flare the 2-3 shift at high rpm. It's because the bottom clutch wasn't engaged which caused it to keep the whole clutch pack from clamping. Now there are several different height rear drum splines, so if you have the right spline height on the drum you can do it, but I have not had good sucess. Search for my other post "everything you never wanted to know about a 904" There is a lot of detail about what I went through. . . Just my 2 cents, and maybe you already have the right rear drum spline, but just be careful!!