The GMC CCKW

Hi!
Have two engines i would like to know more about
Nr1 Gmc 270558504 inline six cylinder
Nr 2 Jea 494120 inline six cylinder
What Engines are those?

Thx Ake

No 1 is a GMC 270 cubic inch, six cylinder inline overhead valve petrol engine. Its most common usage was in the GMC CCKW 6x6 2-1/2 ton truck and DUKW 6x6 2-1/2 ton Amphibious Truck.
It has a bore of 3-25/32" and a stroke of 4" It was originally governed to 2750 RPM.

David