Dakuda,

I think you are dead-on right that with a stock stroke 340 that the Air-gap is the way to go; I remember years ago running 70's era ported J's that probably flowed real close to an OOTB Eddie on an 11:1 340 and the old LD340 dual plane would handily out et the strip dominator in a 3200 lb dart 4 speed with 4.56 gears. (the 1/4 MPH were very close as I remember). It wasn't until I raised the floor of the single plane with epoxy (high tech for 1979!) that it picked the velocity up enough to catch the old dual plane. The short 3.31" stroke loves runner velocity, even with deep gears and especially with the wide gear spread of an automatic. A 340 has to spin almost 7300rpm just to get to 4000 ft/min of piston speed.

That's awesome performance for a stock eddie headed 340!