Encasedmetal's 63' GMC stepside build

[encasedmetal]

Also- 2 things I'm concerned about
1. the rear end- I have a 12 bolt out of a 84 chevy and supposed 2.xx gears. obviously I need to switch the gears out but is that trans gonna hold when I put some power to it?
2. white wall tires- typically these are thinner tires than I'd like for traction purposes so I'm thinking I need to go with white walls and get something in the 10-11" range for the rears at least. however this defeats the look I'm going for so any thoughts on how a painted wheel to achieve this might look?