Wondering whats up with summits complete fuel system -6an(3/8") seems small to flow 140gph at 7-9 psi or am I missing something? Also the regulator they give you flows only 90 gph is that gonna choke out the 140gph or is it underrated?

I have a Summit pump and a Holley regulator. I ran it through the factory 3/8 line and it filled a ice cream pail in about 30 seconds. So yes it does flow around 140gph. I think the filter and pump location play into if it will perform as advertized.

The 140 gph is free flow, it will pump no where near 140 with resistance on the other end. See the MrGasket web site, then go to Mallory parts, and check out the Flow Chart for the Mallory 140, you will see what I mean

My cam swapper said a good electric pump can take care of over 1000hp with 3/8 line and the right pump/
its a very different story with mechanicals, but, its easier to push than pull is the bottom line I guess.

Matt