Need info on 1967 Shelby intake vs. factory tunnel wedge

I have a 427 with a 428 crank in it with a .030 bore making it a 454. I am using a set of Edelbrock 6009 that have had some minor work done. The cam is a solid lifter with 246/256 and 584/594 duration @.050. The compression ratio is 10.4 to 1.

The engine is making 530 horsepower @ 6100 rpm (not taken any further) and 550 lbs of torque @4200 rpm currently with the Shelby intake.
Horsepower and torque figures fluctuate instead of staying at a nice curve which the engine builder said was due to the lack of a good intake ( like the single plane 2x4 tunnel wedge).
Given this information I would like to know how much horsepower and torque difference the tunnel wedge 2x4 intake would make over a stock 1967 2x4 Shelby intake? Also what is your opinion on how it would smooth out the torque and horsepower curve? Thanks in advance. Mike