7875 + 5.9 + E85 + Megasquirt

Those are what I have in mine, they work good and plenty of flow for your set up.
Would love to see your tune. Are you running E85? The injector dead time settings are impossible to nail down for me. I’m just running with default values for now. Bosch Factory or ID2000 data (which is what many people recommend) won’t even idle.