Steering and tire pressure

[bnchief]

Having just redone my model a steer box rebuit tight no binding shortened pittman arm synthetic grease teflon cups on drag link and and tie rod all ball are round and not worn. I have the car up on jack stands it seems a little stiff maybe because everything is new and snug but car turns from side to side no binding and is easy to turn. I am thinking air pressure could help this some i believe standard is 35 psi my tires are firestones could one bump the pressure a little. Also would radials help this? This is a 1930 tudor with standard wheels what size would you recommend.