The Merc pump is said to flow at least 110gph while the Airtex equivalent is only listed to flow 40gph on Summits website. It supposedly has a different diaphragm, I don't know what else is different internally. Just a concern if you have any mods, 40gph is pretty low.

Not to start a tangent off topic, but where do you see that Merc's does 110gph?

Airtex shows 40gph at 1800 RPM free flow, not mention of higher RPM

Currently running triple Holley black 140's.

Good point, if the output is anywhere near linear, that equates to 122gph at 5500rpm. The CV pump is rated 120gph at 8000rpm so this isn't that far off. If you add the Keith Eckert valve body to a new Airtex pump you would have some serious flow. All that for about $260, I will be ordering mine this week.