I believe the K/10 cab has the removable hump in the floor & your c/10 has no hump.
It is doable.
With a little bit of work you can make the K/10 hump work with the existing C/10 floor.
We did this back in the early 80's, when a friend of mine had a 66 C/10 with a 3spd on the column, & put in a 4 spd.
He cut out an opening in the floor where the hump would go. it fit perfect. Just leave enough of a lip around the edge of the hole
to set the hump on, then drill holes where the bolts go, then bolt it up with nuts & bolts.
That was one of the things I liked best about the removable hump, it made swaps like this easy, & easy access to the transmission.
GM kept this set up until 1984 & got rid of the removable hump.
Last edited by JeffL; 03/16/2014 5:26 PM.