Are you confident that you'll get the maximum amount of power from the Dual TBI's? Theoretically it will flow plenty, but can you get it dialed in tune-wise is the question.
I'm surprised you didn't give the P4 upgrade a try. You could have run that in SD or even the Hacked MAF Code. It would have required more tinkering, but a hell of a lot less than the EBL upgrade. WB02 readout can be integrated, along with Fan On/Off Temp Thresholds.
My all roller 305 w/ comp .496 lift cam and valvetrain kit (stock built bottom end minus flat tops), ported vortecs, edelbrock victor jr, and BB tbi I dynoed @ just under 240 with a base tune dialed in. I doubt you'll get 480 like the engine is built for, but you'll come close. ;-)