[Barry_R]

Pretty common pressure values are between 40 and 50 pounds. The common aftermarket EFI systems are usually looking for around 45 although OEM stuff can be much higher these days. Like Rick I use a return system.

Best pumps for long term durability are OEM style Bosch, Carter or Walbro stuff. Race pumps like the Aeromotive or Weldon are higher output but seem to be shorter lived. Lots of guys prefer to run a pair of the OEM Bosch pumps for the proverbial best of both worlds.

Most common injector sizing formulas are referenced to published flow rates, which are in turn based on +/-80% duty cycle. Smaller injectors will generally have better controllability at low flow - nicer idle and part throttle behavior.