running out of breath in the 1/4 mile

We purchased it last Nov or so from Mancini; that might have been the last of the M6902's with the 4-6 psi outputs (unless Mancini or someone can order a special lot), so the alternative right now is to get the M6270 and a regulator after it (such as Straightlinespeed posted in post #41).

We started up the new 340 with a stock pump on it like the OP has, but we just figured it would be better to head of any fuel starvation issues to go to something where the actual flow and pressures were well documented for 400+ HP. The M6902 and M6270 use the same ole casting parts that Carter has been using for a long time, with the 6 or so screws holding on the bottom housing so you can reorient the inlet and outlet if need be.