BowtieJunkie, I don't know if you were able to compare yet, but I have. I ordered a core from rockauto (#OSC 98553) that is identified for 1978 Chevrolet K10, NON-A/C w/350. The core was less that $40 including shipping. This core fit with no issues. I think the install is easier in the C6000 than my C10.
