6 Pack vs. 650 4BBL?

Hi Guys,

I would like to update the 74- 413 390 HP dart, with 3:55 gears and all conversion hardware.
I use a 600 Eddy.
What 4 bbl would satisfy this RB for mo" HP.
I think maybe 2X4 setup. would a 780 satisfy the urge. I am installing dual snorkel scoop,
to fit 14" or 2x4 cleaner.

Thanks, ddume in VA,