The 64/65 K positions the engine about 1 3/4" further ahead than the later 67/70 K. So if a later K is being used the engine will be real tight to the firewall. In my case with trying to run kickdown linkage and a heater, the heater core spiggots interfered with the linkage. Also if the later K is used then the transmission crossmember will have to be modified.

HTH
Randy