Today I changed the torque tube in my 47 sedan delivery from the original 4.11 gears to a 53 Chevy Power glide torque tube with 3.55 gears. I'm hoping it allows me to travel on the Hiway to shows further away from home without the engine screaming. Took about 5 hours, changed axle seals in the process.
Firecar, one thing , besides the speed capabilities of your sedan delivery, you will notice is when you go to pull away from a dead stop, like at a traffic light. And if you are on a slight upgrade you'll really notice this. I'm not going to spoil your surprise - just say that I found out when I made the same alteration to my '50 convertible and '51 sedan. Please let us know how you like your change-up when you get it out on the road.