I have a 6" susp. lift. I have a stock front driveshaft. It doesn;t have a bunch of splien engagemjent obviously, but it's been working fine for quite a while now. Just today I put on the ORD HD front shackles. I think they are supposed to raise the front by 1/2" or so. Well, just using the jack to raise the frame and let the axle droop, I was able to make my front drivehshaft come apart!!!!! I put it back together and measured the spline engagement with the axle at rest (you know, just sitting there without any jacks or anything.) It only has right at 1 inch engagement now! I don;t think the kind of wheeling I do requires major flex. I know I *should* retube the shaft, but I don't have the cash flow right now. PLUS, this weekend the SO and I are supposed to have the inaugural run of the new truck, so I want someone to tell me it'll be OK. I'll carry the 7/16th wrench with me just in case it seperates. I fiugre that I'll let off the gas when the susp. droops to prevent twisting the splines. Other than that, I dunno. On a side note, my truck has been in a state of disassembly since Thanksgiving weekend. I am seriously planning to enjoy myself this weekend -- Mike <font color=blue> At some point I'll be done building my truck and can actually go wheeling. Until then, I guess sex and alcohol will have to do.