On top of my 416 stroker.

Thermoquad w/LD340 or a Holley 750HP double pumper on an RPM Air-Gap?

95% street driven with 3.23 gears and a 2800 stall.
Comp solid roller 248/256 dur@.050 576/582" lift
Edelbrock heads.
11.5 to 1 comp.(yes, it works in Denver)

I'd kinda like to give the ole' Bakelite Wonder a chance on this motor but I think the holley is ideal for this setup. My thermoquad is the original that the car was born with(1973 #6139). I also have the Holley 750HP and the other two intakes. I just can't decide which way to go.

How much do you think I lose with the LD340 instead of the Air-Gap RPM?

I don't know why I'm having so much trouble with this....

Benny

IMHO,the LD340 is right up there with the new RPM airgap in performance

I would use the LD340 with the Holley. In fact I am - on 2 units and am very pleased. That is what is on the signature car. Runs on all throttle - no bottle.
If you use the LD340 with the Tquad you will have to either auger out the secondary casting so that the Tquad throttle plates can open or use the spread bore adaptor.
As for loosing anything here is my little story from a few years ago:
I was in the process of ordering an Airgap from Ray Barton and had him on the phone and teh order placed and giving him billing info. He asked what I was running now. I told him and LD340 and he told me to keep what i have as any gain (if any) would be minimal.
Not staisfied I called Edelbrock tech and the person that I talked to there was familiar withthe LD inakes and he told me the same thing. Go figure. Old technology can't be all that bad.

I agree with joedust451 and scratch; the LD340 works well on a 340, especially with a T.Q.

Here is a pic of my 340, LD340 and an adapter. The engine had exceptionally strong bottom end, mid range and top end, David.

I like the RPM Air-Gap with the Holley, but with 3.23's, I'd consider a vacuum secondary carb, instead of a double-pumper.