Which SB intake should I run? AirGap, M1 or Victor 340?

I've got all 3 intakes and I need help figuring out which one I should run. I've been running the Air-Gap but I'm wanting to pick up the ETs some. The M1 and Victor 340 are untouched single planes. The best it's ran so far is 11.35 at 118mph with 1.57 60 foot times. Here are the car and drive train specs:

1968 Fastback Barracuda
318 stroker (390cid)
K1 4" crank
Eagle Rods
Ross flat top pistons
Edelbrock heads (OOTB)
Air-gap dual plane
BG 750 silver claw
Comp solid cam (.540/.555 252/262 @.050 106 lobe sep)
TTI headers
727
Dynamic 9.5” converter
3.91 gears in a 8 ¾ sure grip
Cal-tracs, mono leaf, Rancho 9way shocks
Cal-tracs 90/10 front shocks
Carter mechanical fuel pump
full exhaust with Dynomax turbos
full interior
3,400lbs race weight
ran 11.35 at 118mph shifting at 5,700rpm

This winter I’m:
putting a roll bar in
pulling out the stock tank and going to a 5 gal fuel cell
Aeromotive 2000 fuel pump
moving the battery to the trunk
moving to a spool
4.30 gears
M1 or Victor 340 intake
Holley 950 Alcohol carb
Going to Alcohol

Hope to be running 10.90s next year.

Any other info needed, just let me know.

AirGap hands down. It will outrun the other two also. Will not believe me until you try it then you will know. That is a VERY good intake. Was a FULL two tenths faster than two different M-1's and made the car leave WAY better. The AirGap range is 1500-6500 which is perfect.

I would say the Airgap for your combo.

I would think the airgap, your fairly heavy and dont
turn it very high so I would believe the torque would
be much better with the airgap.... JMO

Depends on the converter stall/flash as to which one will work better. your weight and gear is right on the cusp. The AG or RPM will make more torque below 4000 hands down but the M1 intake runners flow close to 290 (better than many Big Block single planes!) and the AG flows nowhere close to that....so up top there's no comparison in terms of peak HP potential...if you have the head flow to use its advantage.

I'm going to run both back to back on my little 341 but w/4.56's and 2800lbs I don't need a lot of torque off the line...that said I do prefer the AG's upper bottom so again it really depends on your flash. with 390 cubes I definately think the M1 has more HP potential. I run a 2" hvh super sucker on the M1 and that made a big improvement in throttle response. The AG/RPM responds very well to porting the 4 plenum transitions to each of its 2 runners, there's just not enough cross section there for big top end power as cast.

Edit: Going to alcohol may also be a factor, you'll meter a bit more fuel per HP so remember that the amount of fuel in suspension displaces the amount of total air you can get through the port. A bigger (and straighter) runner can be advantageous in that regard, especially in a long stroke motor that doesn't need a lot of runner length to make torque.

The M1 is basically the old Holley Strip dominator (slightly improved) and is on par with the Victor, the super victor is a step up on big motors with a lot of port or moderate size motors turning big 7800+ rpm.

I'd run the Victor or the M1 if it were mine. The 340 I had in my 3300# Dart was 11.2-1, ran on pump 93, ported Edelbrocks, hydraulic cam, 237/242 @ .050, .586/.592 lift, 750 Quick Fuel carb on a Weiand X-Celerator. A 727, shift kit, 9.5" converter that flashed 4400, 4.30 geared 8 3/4.

It ran a best of 7.24 @ 95.04 (1/8), it went 1.53 60' several times and would run low 7.30s in the heat with 1.56-1.57 60's.

It now has a 10.8-1 408, a 260/264 @ .050, .628/.633 lift flat solid, same heads, Victor intake and a Bigs 950HP. The 9.5" converter was set up for the new engine. It's made one clean pass and ran 6.61 @ 102.25 with a 1.41 60', untuned.

You're stroker should have plenty of bottom end for the single plane .

With the winter mods you plan to make, Victor 340 and a 1" open spacer.

One thing is you dont say what your stall is but even
with the gear change it would take you up to about
6000 rpm and really thats about what a stock engine
would turn.... the only difference is that you will
be moving more air... I think if you port the airgap
it would be fine.... build for torque and let the HP
fall where it may

I'd use the Victor and get a converter that will be compatible with the torque curve. If your goal is to run 10.90 the Airgap won't likely get you there. I don't like the M1.

3000lb Cuda. 340 .030 STOCK Eddy heads TRW 11:1 pistons stock rods and crank. Eddy AirGap, went 6.71 with a 1.41 60ft pulling the front tires everytime. 5000 stall Turbo Action with 4.88 gears. The AirGap will go WAY faster than 10.90...totally disagree with that. Mine was running around 10.60 in the 1/4.....

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!

Went from an air gap to a Victor 340 ( with a Wilson 4 hole tapered spacer)with a very similar combo to what you are presently running ( except 408 and much heavier car ) and got positive results shifting at 6200. With the carb and gearing change you propose, I think you will run out of manifold with the air gap - even with OTB heads.

We shifted last year at 5,700 with the 3.91 gears but with the 4.30 gears and alcohol I expect to shift around 6,200 - 6,400 RPM.

I can't exactly remember but I think the car stalled around 3,800 - 4,000 last year and with Alcohol it should stall 200 to 300 more.

Does that make some of you that thought the AirGap was the one I should stay with change their minds?

Keep in mind I have all 3, just wondering which I should start with and if I'm happy with the performance I'll stick with it and sell the others.

Just looking at the M1 next to the Victor 340 intakes the M1 looks better, but I don't really know what make one intake better than other so that input isn't even worth .02...lol

Wade, I would think that with the changes planned, a single plane would be the right move. If it were me, I'd start with the Victor, as I think more have had success with that vs. the M1.

I swear I'm not saying this just cuz I'd buy that AirGap...no really . But if you want to sell it...

The air gap intake will work best with the OOTB heads...hands down. That comes from some of our dyno testing on 4" crank engines.
The M1 with porting will make close to the same HP and TQ, but the air gap will do it right OOTB!
I would add a 1" spacer and jet up 3 jet sizes (example:from 70 to 73) front and rear.

A few years back we messed with a M1 vs air gap on a 365 cid flat tappet 10.5 1 mud motor that had ported J heads , we ended up with the air gap and a larger carb 850 than the 750 we ran on the M1, the air gap made better power thru the rpm band, the cam stopped @ just over 6500 so the M1 had no advantage up top

One intake that hasnt been mentioned, is the weiand excellerator, its an excellent torque producing piece. Its a " mild" single plane.

My little brother went 11.48 with that intake, stock eddies, on a 360 at a hair under 10 to 1 compression, and he actually has a bigger cam than the combo needs. It still went 1.48 60 foot at 3300 pounds as i recall with low cylinder pressure.

I used that same intake a few years back on a mild 416 and later on a 10.70's ish 416. Its a very underappreciated intake that works well at 6000-6500 rpm. In fact i took off a air gap and ran that on my inital mild 416 that went only 11.70's and the car liked it better than the airgap at the track.

Just food for thought

Only way to know is try the others and then you will know. TRY IT, too difficult to guess at.

I've never run the Eddies out of the box but IIRC they flow around 235-ish at .500. You can pick up 15 cfm pretty easy just fixing the VJ, bowl blending and opening up the pushrod pinch....well worth the work for another 20-ish hp and higher peak power RPM IMO. Edelbrock is notorious for tight guides so I do this as a matter of course anyway.

If the manifold outflows the intake port by a wide margin (let's say more than 10%) you're never going to realize it's full potential (as Brian I believe eludes to) and often the intake will get blamed for the mis-match. The M1 (strip dominator clone that it is) flows about 285 and is very balanced runner to runner and has decent taper and an agressive approach angle from the Plenum...arguably BETTER in many ways than the Larger Victor. As said the RPM simply doesn't have enough cross section where the four main branches split to its individual runner pairs to make big power upstairs ON a DEEP BREATHER motor, but it probably keeps up with the OOTB eddie just fine.

Again on ALCOHOL I'd want a larger straighter runner because you have to push more fuel (bigger jets) through the carb to the valves....Liquid fuel takes up space and alcohol takes more room than Gas (petroleum)...if you think about that that leaves LESS room for the air and you need both to make power. As Wade said torque will improve with the alcohol 9it always has in my experience) so the Perf RPM's upper bottom-mid range advantage is going to be offset by the broader torque curve and the smaller cross sections will very likely choke off the big end power of a 390 incher.

A small bore long stroke (3.94 x 4)combo is gonna make torque with any manifold....you could put a torker on an 8:1 455 Olds Vista Cruiser (4.125 x 4.25) and still pull a 32 foot travel trailer! But with the Strip dom/m1 you do have to watch the powerband, especially with an automatic, a high RPM single plane can and will fall out of the 'sweet spot' if you don't have enough flash to cover the wide gear spreads vs a 4 speed.

I've never run a victor on a stroker motor but ran a few W2 versions that were like a light switch in terms of powerband...all of it upstairs! Wouldn't fall out of a tree below about 4200 on my old 4 speed car but came on like a nitrous shot above that! Had to keep the revs way up to keep it in the happy zone for sure. But it'd probably work real well on a 416 incher with good heads and 3400+ stall.

Curious Wade, 2 1/2" or 3" exhaust??