chevykidd88

i just installed a six inch lift in my 76 chev /12 ton, i am being told by my local driveline shop that they cant make me any driveshafts cause of the pinion angles,the shims that came with my springs i thought would be enough for the lift, what are some things a can do? or what do i have to do? do i have to run a cv shaft? or will shims be enough? the transfer case is not dropped at all. thanks for the help