What was the reason of GMC having their own inline while the Chevy side had theirs? It seems from what I see that the GMC is the better truck powerplant, so why didn't GM continue to advance it and use it in both GMC and Chevy pickups?

I could never grasp the reason of this or GMC's Monster V-6's.......Granted most people either love or hate the V-6's(I happen to really like them), but why didn't they offer them in the Chevy's? A great low end truck motor built for work if you ask me.

Love Old '67-'72 GM Pickups! Dare to be different.....Running GM Inliners, GMC's MONSTER V-6's, and real inline power, Cummins, in Central PA.