A 1948 4400 is a 1-1/2 ton with a 161" wheelbase.
The cab, including doors, is the same as the smaller trucks. I'm not sure about the fendersand hood but I think they are the same as 2-ton, which are bigger than pick-up ones.
The 270 is a great motor. It is a real truck motor. As GMCpanel inferred, the chevrolet trucks came with a car motor.