I'm gonna chime in on the side of no power steering as well. I'm running monster truck tires with a stock '54 steering box, and it's effortless with the tire pressure topped up. I still won't run at freeway speeds, the gearing is all wrong and (do not try this at home, kids) an unladen tonner literally hops from one expansion joint to the next on top of the Alaskan Way Viaduct, bouncing off the tires without flexing the springs at 45 mph... I won't be doing that again.
My most important upgrade was dual-reservoir power brakes; a power assisted disc/drum kit is probably the biggest improvement for the money.
