'50 3600 Just a couple questions...

[bmnk]

A few days ago I was offered a deal I couldn't pass up on a 1950 3/4 ton truck, that is all original. I think I've decided to keep it stock because it's very solid and it runs, but I am thinking I want to do some minor upgrades like replace the brake lines and add a dual master cylinder, and replace the rear axle so I can maybe get above 50mph without having to be going downhill with the wind to my back.

My question is does anyone have any recommendation to the best fitting rear axles for the 3/4 ton trucks. I would like to retain the 8 lug wheels. Or can I find new gear ratio to replace inside the pumpkin? I know my '52 has a late 70's Camaro rear axle, but I really want to stay away from the 5 lugs, and keep the truck feel about this one.

Also I'm thinking of replacing the wire harness, as it's still the original cloth covered wires, and they are starting to show there age....should I go ahead and change to 12 volt system while I'm doing the wiring anyway, or will sticking with the 6 volt be just fine.