The half-open half-torque driveline is how they did it. No one has changed it.
Half ton frames do vary a little. The rear cab mount was in the center in '47 and '48, maybe longer. Early ones are built for lever action shocks. I think that changed in '50, but any list of changes by year will mention that. '54-55 have a different kickup to allow a deeper bed and also have different bellhousing crossmember to take a different bellhousing.
GMC had a different front crossmember to mount the longer GMC motors.
You sound like you want a stocker. That being the case I'd either go with a 1/2-ton '50 to '53 frame unless your bellhousing is the '54/55 type.
