Looks like we've managed to pretty much hijack this thread.....my apologies to the OP.

I have no idea what the 5.7 in the station wagon uses for a PS pump. I kind of suspect they may be using the one that came with the motor, whatever that is.

As far as the Saginaw pump there were a few way that people used to reduce the pressure and as far as I know most are still available including the shims, a new relief valve and even pumps rebuilt to drop the pressure.

I heard recently that a Saginaw pump speced for a late 60s-early 80s Corvette operates at a lower pressure. That makes sense as those power steering systems used a slave cylinder and draglink mounted control valve.

If that is in fact true I would be careful where I bought the pump from as I suspect from a rebuilders standpoint a Saginaw pump is a Saginaw pump and chances are you would end up with the higher pressure pump.