As I recall the '37-38 T14-T16 GMC's that originally came with the Olds flat-head 6 had the radiator mounted to the front of the core support which required an extension on the fill neck, which the Chevy 6 did not need.
I put a 270 GMC engine in a '38 Chevy (car) in 1951, had to deal with the 2" added length, moving the radiator to the front of the core support. I also had to use a Chevy short water-pump. Wm.
