Firstly, after a 100 miles of driving, I spun a little on icy grass in my yard; got out and engaged spicer hubs and 4 hi; worked great. Today, went out and spun in yard again; really cold and mushy; got out and locked hubs; nothing, just back wheels a digging. Made several attempts to engage-disengage both hubs and t-case; still no 4WD. Question is, could the hubs or t-case be frozen due to cold? It was about 25F most of the day. Or should I be worried its something else? Drivers side hub seemed like it never locked. Turning the hub, I could move it in and out about a quarter inch. Have appx 42 inch eyetoeye 9 leaf pack for front spring. I have 5 leaf pack in rear with 3 and a half inch block. I'd like to keep the same height without blocks or shackle flips; would a 8-9 leaf spring from a 87 2500 fit in the rear? And is it beefy enough to make up the 3 and a half inch block? Btw the rear spring I have now measures 52 eyetoeye.