Hi guys-- Made a mistake on the first post which has been corrected. Accidentally used the flow numbers from a different Walbro pump. Too much eggnog
With the correct flow numbers used, the relative flow differences between the 3 approaches are even greater. The basic gist of things is that keeping the factory pump in there (and not replacing it) and running the Walbro E85 pump in-line means that:
1) You are not sacrificing pump output to feed the venturi jet. Which means more fuel flow to the engine.
2) You are keeping both pumps running at a lower pressure ratio which is especially important for the Walbro pump which is not designed to run a differential pressure of a continuous 72psi. This means longer lasting pumps.