My Dana 44 hit with 5.5" of lift and the crossmember hacked when I hit speed bumps. My driveshaft would hit the ypipe on compression before my diff hit though. This could be solved with a LP EB diff (mine was a HP F150 diff narrowed to EB width) or a FW axle. Since Joe has the FW axle, I don't think he will have the problems I had. The only I way I found to fix thiswas to move up to a 7-8" lift. Now I get plenty of up travel- when the axle is flexed, the passenged side must be drooped enough that the angle of the axle is such that my crossmember doesn't come close. It is a fine amount of lift with 37s!
I am not saying you can't run 5.5" of lift and get a solid amount of uptravel, but I am saying that you can't run a narrowed HP Dana 44 and get a significant amount of uptravel. I tried to hard. I really like 5.5" and 35s. I mocked my axle 2" forward, then 3.5" forward. 3.5" was a far as I could go with the buckets set up like I did.
My cross member is pretty much hacked on the front huge. When it was making contact, I cut the crossmember so that it fit around the pumkin, and the diff would go with in an inch to a half inch of the oil pan (crossmember between). That is why I decided to leave the stocker. The way I did it, it is still strong, and it is a barrier between the pumkin and my oil pan. It would be pretty tough to build one that would serve the same purposes. Besides, I got plenty of other junk on the "to build list".