It actually does affect it more so then two top shifts for some reason the rails have a higher chance to hit. I may be wrong but all top shifts I have done work with a little bumping but mine I had to cut about a half inch off. If you looked at the picture Halladay posted it shows where and which rails he cut. You odviously dont have to cut the rail going into the adaptor because it goes to no where. You need to cut the rail that sticks out of the crawl box going into the adaptor because it hits the 4wd rail on the rear case. I may have just said taht wrong but thats the on you'll want to cut. Just be carefull not to cut it past the marks for the detent ball, I left about a quarter or more of an inch after before the cut. I think I also cut the other rails so they didnt stick out of the case at all when shifted it just seemed like a good idea lol.