The trucks started using the good tranny bolt pattern in '47 and the cars started using it in '55. What this means for you is that if you use a 47-54 truck 3spd, you can use the torque tube setup, but you can change it later on to open driveline without needing to change the bellhousing. So using the 47-62 truck or 55-62 car bellhousing would be my recommendation. It will allow you to use either drivetrain style. Your stock '48 car tranny will not work, however with the later housings.
