Doesn't matter which one that you use e.g. 4 or 6" BDS kit, both will fit in your garage. I have the 6" with 35" tires and I fit in mine, it is very close though. What doesn't fit is the radio antenna, the stock one is to stiff and drags the garage door to a point where it seems to want to break. What I did is just remove the antenna since I do not ever listen to the FM radio, but if that's a problem for you then you'll want to use a short antenna.