89, 350fi, np241 4" lift kit was installed a few years ago. the shop that did it failed to make me aware that the driveline was almost all the way out of the driveline hole. the subsequent vibration tore up my 10b, which i replaced. i also installed a cv driveshaft, which didn't last long. it was rebuilt, and i decided to rebuild the 12b i just installed, to be safe. the driveshaft broke again (the centering ball @ the cv joint); it was pointed out to me that the 12b was angled wrong, so i had my spring perches rewelded, and the driveshaft rebuilt. the freaking thing is broken again, and i don't know why. i don't wheel the piss out of my truck, and i don't think 4" is a big lift. i could really use some help in trying to pinpoint a reason for all this.