Shooting the breeze. What’s the 1/4 mile time of a 340 challenger?

[RUNCHARGER]

Agreed: I think if your AVS is operating correct and the 440 one is operating correctly it would be more like a 20HP increase. Worth the swap, I'd be tempted to swap on a nice, tight new AVS as well but I understand the appearance issue.

[kawahonda]

20 HP increase for looking stock is damn worth it.

Now to figure out which Carter AVS carb #s I should be looking out for and to begin looking. Maybe this is the first step before messing with the intake or the cam....seems to be a period correct and proven thing to do. I'll check in my manual tonight and pull up some numbers.

If anyone has any proven 440 runners sitting around, let me know.

[RUNCHARGER]

If memory serves a 70 4 bbl 340 was rated at 290 by NHRA and the Six pack was rated at 315HP by them. That's where the 20HP came from in my estimation as well as what they felt like.

[kawahonda]

Yea! You can essentially have a 6-pack with a 4-barrel carb. maybe the poor man's version?

[chargerdon]

Don't get me wrong!!   I love my 74 Challenger with 360 (Eddy carb, RPM air gap, Patriot headers, Lunati voodoo cam, 904 automatic with shift kit, and 3.23 sure grip with the 14" 60 series wheels and tires.   I expect it would run in the low 14's to maybe mid 13".

However, Motor Trend has an article on the quickest 15 SUV's... All of them running in the low 11's to mid 12's and 0-60 times below 4 secs.   Progress...   BUT not one of them sounds like my Challenger with the Flowmaster 40's and the wonderful slightly lumpy cam !

[kawahonda]

OK, for a 440 carb that's period correct I would want to be looking for:

4740S (ECS)
4738S (CAS)

My current carb is an ECS carb. I doubt ECS or CAS matters in the year of 2019, correct? I should be looking for either/or, everyone agree? Assuming the only difference is that the CAS carb does not have that little plunger thing with the lever on the side, otherwise the exact same thing.

Not aware of any other Carter AVS part #s to be looking for.

[1 Wild R/T]

4618S  69 440 HP Auto
4738S 70 440 HP Auto
4968S 71 440 HP Auto

[kawahonda]

There's actually lots of other part numbers I assume that will work too.

I'm currently deciding on two 4640s from members on the abody forum. Seems like this is a 440 750CFM auto carb that shipped in 1969. It is an Auto carb. Still a bolt-on exact fit?

[1 Wild R/T]

Should be..

[kawahonda]

Thanks Randy! He's sending me some pics soon of the rebuilt one. Another member has one that's in a good shape that may need a rebuild. You still in the market for one?

Stupid question to ask now, but would there be and negatives going to a 440 carb? Obviously some tuning would be required, but I assume once that's done, an all around performance increase or more of a mid-top end range increase? Slightly less MPG (not that I'm worried about MPG, lol).

[gzig5]

I'd consider the new 800cfm AVS2 that just came out.  These have gotten really good reviews and the annular primaries should help with the larger CFM.  I'm putting the 650 version on my 340 with an Air Gap intake soon as I get back from my business trip.

[1 Wild R/T]

Me in the market? Nope!

Performance gain will be mid-high RPM's, down low it may soften very slightly... Doubt you'll see any change in mileage..

[kawahonda]

So are we sure that a 440 AVS will work on the factory 340 intake? Being that with the 440 carb, the primaries are the same size as the secondaries (1 11/16 as opposed to 1 7/16).....would the larger butterflies even work on top of the primary bore of the intake?

My carb sits on an insulated spacer from mike's kits anyhow:

https://www.carburetor-parts.com/Carter-AVS-Carburetor-Kit--69-71-Chrysler-Plymouth_p_653.html

I'm just using the spacer too....no other gaskets from carb to intake.

[1 Wild R/T]

Has anyone ever told you that you over think stuff?  Just bolt the damn thing on already....

[kawahonda]

Sent you a PM...