I ran into a similar problem with my truck. When I bought my truck, the previous owner had hired somebody to remove the engine so it could be rebuilt, and hired a different person to reinstall it. Somehow during the process,things were lost,among them the throttle linkage.
I bought a throttle linkage assembly complete from a wrecking yard which included the "through-the-cab" part.It supposdly was for the same year and looked correct but would not work.
My mounting pin was on the block to the rear of the manifold. I solved the problem by buying threaded rod and threaded ball-socket ends at the parts store. I cut the threaded rod as necassary,screwed on the ball-socket ends to make up the rods which were adjustable to some degree. The only part of the original assembly from the wrecking yard was the v-shaped bracket which mounts on the pin screwed into the block.It works well in one sense,but I still have not yet contrived a satisfactory return spring hookup.
meansam