My truck did 408 hp with a single SD electric pump (very slightly modded Bean's Fuel System) and a stock muffler the last time I dynoed it with ancient 2002 Dieselpower tunes. Pressure at WOT dropped 4 psi with Maddog 160 cc stage II injectors. Much wider torque band than the factory OBS pump. Haven't dynoed it since with the Terminator, new 4" exhaust and Jody tunes yet but it was stronger than before. My guess is the single SD pump is able to support about 420 or more hp. The truck dynoed 399.8 hp and also ran 14.508/1.99 60' with the factory mechanical pump so its not a happy dyno I'm running on. Oh, yeah this is also with using the 1.0 housing OBS turbo with 80k miles on it with stage II injectors and a Banks Power Pack.
My guess is that if you use 3/8" fittings on the Bosch -044 it doesn't do much better than the SD pump if at all. It probably gets the higher flow numbers only when using the larger AN-10/12 fittings and hose that it can accomodate. My next fuel mod is going to dual SD pumps/AN-10 or 12 fuel lines to feed the BDs I'm installing in a while.:redspotdance: