I have a 77 K5 Blazer 6" lift and 35" ground hawgs. The truck originally came w/ a 400/th350 does it have a 205 or 203?? When I try to shift into 4wd the case goes into high, low and neutral w/ no problems noises etc, but the front driveshaft will not spin. Any suggestions?? Do I need to remove the t-case most likely in order to repair?? Any tips would be appreciated.