Since I got no response in the IFS forum, I'll try it here. I've got a 98 Tahoe that I'll be doing a SAS on. Of course it currently has the NP246 AutoTrac t-case. I know that it's not supposed to be used for a solid axle truck, but why CAN'T I use it? Is it just because the all wheel drive won't work or is there another reason. I've never used the AutoTrac feature as it is now. I don't see myself using it in the future. Also has anyone ever done an SAS but used coil springs instead of leafs? Not coil over shocks mind you, just regular coil springs. I know the ORD Blazer was coil over shocks for a while, but I was looking for a more conventional set-up. Thanks for your help.