After I swapped the 6.2 for a 350 I ran a standard p/s pump with the return lines teed. I never had any problems with it setup like this. The only thing I did notice occasionally was that at a stop or slow speeds - like entering and exiting a perpendicular parking space - I could turn the wheel fast enough that there seemed to be a "lag" in the power steering assist.
I'm the paranoid type so I eventually swapped in a hydroboost pump to work with the serpentine belt setup I also added. With the 37s it doesn't seem to have any problems turning the tires at a dead stop. Haven't really trail tested the 37s yet though.