TF front axle shims?

[roger55]

I've installed a CPP 400 power steering box in my '57. I'm keeping the straight axle and stock springs both in the front and rear of the truck.

I want to put some positive caster in it for a better steering feel. I've been told that with power steering I want about 4 degrees of positive caster. I'm about ready to install the front axle back onto the frame after blasting and painting everything.

Can I choose which shims I need now? Are these TF trucks 0 degrees caster without any shims?

Or, should I just install the axle now with no shims and wait until until the entire truck is assembled and measure the caster and then go from there?

Btw, when I disassembled the front end, it had 1 degree shims installed. But, they were installed in the direction to decrease the caster. I wonder if a previous owner did that to make it steer easier or if it was factory.