Have a '90 K5 w/ TC 3" front springs and 4" blocks in rear. Vibrates at slow and fast speeds. Someone referred me to "Tom Wood's Custom Driveshaft". They told me I needed to have a new shaft with a CV joint up front (behind transfer case). Angle difference b/t slip yoke and shaft is 9 degrees, and b/t shaft and pinion is 4 degrees. Has anyone tried this? I want my truck right and don't mind spending the $450 he quoted me, but wanted to get some input before I did it.