I converted to five lug axles. I wasn’t interested in the stock rear end ratios I could choose from, or the rear brake parts supply/cost issues. It wasn’ti an easy choice to remove the stock rear end, but I plan on driving the truck regularly and keeping it for a long time, so I went with a GM 8.5” rear end with 3.73 gearing. I converted to a 3100 front axle and then 5 lug disc from there..
As far as the crossmember goes, my crossmember is stock and I have not removed or modified any crossmembers. My understanding is that the 3100 and 3600 frames are identical from the front up until under the rear of the cab, where things begin to change... not sure why this kit didn’t fit your truck...?
