I would say that any pump providing 125 to 140 gph should be fine for your application, depending on how often you're in the secondaries. Start off with -8AN (1/2") from the sump to the pump with a good inline filter (one that can be dissasembled and cleaned) in between, continue the -8AN from the pump to the engine compartment to an adjustable fuel pressure regulator. Also, mount your regulator in rubber to eliminate vibration that may give you an erratic pressure reading, you want a good solid 6.5 to 7 psi. on the outlet side of the regulator. Then from the regulator, run a section of -6AN(3/8") line to each float bowl.
With this combination of pump, and the step down in fuel line diameter, it will supply enough fuel at the proper pressure to feed your motor with those gears at the rpm range you'll be running. If you haven't purchased your carb yet, you may want to consider a 850 vacuum secondary, or possibly a 750 dp. Your engine will probably like these better for the street, alot crisper throttle response, and easier to be able to set a proper idle mixture. The vacuum secondaries work off of engine load and demand, so you may actually gain some mpg-that is,if you care about such a thing!
