you could go with a 79 older van column, but some mods to do for firewall mounting and seal and such, oh and need turn signal switch wiring adapter from chevy parts counter, have fun
72 up pickup one be wiring nightmare since ignition is in column in them
rear spring perches removal requires removing the frame rivets that hold them to frame rail
grind and punch them out
its not that bad if you have grinder and patience and goggles and earplugs and soem grade 8 hardware
whats wrong with the 68 column ??
whats specs on the 68 ? 68 chevy trucks are my all time number oen favorite trucks in the entire world, my first chevy was a 68 truck years ago, miss it alot, had a bunch, all gone now and cant find one anywhere now
good luck