You didn't say what you have for ignition, so I will go ahead and tell you what is needed:
Electronic distributor - I use an MSD limited to 18 degrees of advance and 20 degrees initial (38 total) on 104 octane.
MSD 6AL (or equivilant) spark box.
I'm using Bosch Platinum fine-wire plugs.
My 2x4 engine is a +.030" 390 w/fully ported '70 heads, dynoed 518 to rear wheels when it still had a Torker & 850 Holley. Now using 2 660 "Center-Squirters" on an Edelbrock UR-18 Ultra-Ram. Way faster now but DON"T touch the gas pedal until it starts!!!
I've sold the car now but the 390 is getting retooled.
