340 intake/carburetor advice

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Kilroy Caldwell

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Taking the stock 318 out of a 1975 Plymouth Scamp, replacing it with a 340 that has had a mild cam upgrade and ported heads. Basically going to be a street car, might occasionally drag race it, after changing to a 8- 3/4 rear end, upgrading brakes and suspension. Right now I'm leaning toward a Weiand Action + 8007WND/ Remanfactured Thermoquad 800 cfm combination or Edelbrock RPM Air Gap 7576/ Edelbrock Thunder E1826 650 cfm, but I would like to hear some other recombinations or advice, thanks.
 
If you are running a TQ, I'd use the factory cast intake for a TQ. Action Plus would work (I like these intakes), but for your application a Stealth or RPM might work better. IF you want another combo or recommendation, I'd run a 750 Holley DP 4779 on the RPM. But again, everything you've listed would work.
 
What gears are you going to run and are you using an automatic or a four speed? It doesn't really matter here other than to go ahead and invest in a good torque converter if your using an automatic. For a mostly street driver you will be hard pressed to find a better cruising combination than an Edelbrock air gap and an Edelbrock AVS2 800. If your more all out performance oriented then use an 800cfm or larger double pumper.
 
Kilroy Caldwell said:
Taking the stock 318 out of a 1975 Plymouth Scamp, replacing it with a 340 that has had a mild cam upgrade and ported heads. Basically going to be a street car, might occasionally drag race it, after changing to a 8- 3/4 rear end, upgrading brakes and suspension. Right now I'm leaning toward a Weiand Action + 8007WND/ Remanfactured Thermoquad 800 cfm combination or Edelbrock RPM Air Gap 7576/ Edelbrock Thunder E1826 650 cfm, but I would like to hear some other recombinations or advice, thanks.
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The 8007 doesn't have the bigger 340 ports. You could make it work, but personally I don't think its worth the effort. I'd go with a factory 340 intake or a performer rpm for a 340. I really like my dual plane M1. Its really the same intake as the 70 340, only aluminum. The weight difference is crazy!
 
The reason for going with AVS2 instead of the Thunder series is that the AVS2 has annular discharge secondaries. Alot of guys say it almost is like having fuel injection. The throttle response is really great.
 
DFX 340 Duster said:
The Street Demon is also a good option. It has gotten good reviews by a couple of FABO members.
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I've heard good things about them also.
I just promote the AVS2 because its what I have the most experience with recently. And it works exactly as Edelbrock advertised it would.
 
318willrun said:
If you are running a TQ, I'd use the factory cast intake for a TQ. Action Plus would work (I like these intakes), but for your application a Stealth or RPM might work better. IF you want another combo or recommendation, I'd run a 750 Holley DP 4779 on the RPM. But again, everything you've listed would work.
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I'd run the factory TQ intake and block the heat off to the crossover. Use the TQ and tune it.

Way better than all the other stuff unless you go to a square bore intake and a Holley style carb (I don't like anything with the Holley name on it).
 
Go Mango said:
The reason for going with AVS2 instead of the Thunder series is that the AVS2 has annular discharge secondaries. Alot of guys say it almost is like having fuel injection. The throttle response is really great.
Click to expand...
DentalDart said:
I have a 650 CFM AVS2 paired with my 340, Rpm air gap 7576, and headers. Runs great!
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Garrett Ellison said:
What gears are you going to run and are you using an automatic or a four speed? It doesn't really matter here other than to go ahead and invest in a good torque converter if your using an automatic. For a mostly street driver you will be hard pressed to find a better cruising combination than an Edelbrock air gap and an Edelbrock AVS2 800. If your more all out performance oriented then use an 800cfm or larger double pumper.
Click to expand...
Go Mango said:
The 8007 doesn't have the bigger 340 ports. You could make it work, but personally I don't think its worth the effort. I'd go with a factory 340 intake or a performer rpm for a 340. I really like my dual plane M1. Its really the same intake as the 70 340, only aluminum. The weight difference is crazy!
Click to expand...
appreciate
Appreciate the insight, I had the AVS2 at the top of my list, till someone talked me up to the Thunder. Looking at stock, will check into M1, it's a 69 motor. I will probably stick with the A904 transmission, and one day, good Lord willing, a 8- 3/4 3.91 geared axle, upgraded suspension, brakes, etc...
 
yellow rose said:
I'd run the factory TQ intake and block the heat off to the crossover. Use the TQ and tune it.

Way better than all the other stuff unless you go to a square bore intake and a Holley style carb (I don't like anything with the Holley name on it).
Click to expand...
Yeah, I ain't a big Holley fan, myself.
 
This or nothing.

IMG_25071 (1).jpg
 
Kilroy Caldwell said:
appreciate
Appreciate the insight, I had the AVS2 at the top of my list, till someone talked me up to the Thunder. Looking at stock, will check into M1, it's a 69 motor. I will probably stick with the A904 transmission, and one day, good Lord willing, a 8- 3/4 3.91 geared axle, upgraded suspension, brakes, etc...
Click to expand...

I had the 904 with 7.25 and it was great.

Just finishing up the 8.75 with 3.23 and sure grip as well as new brakes and suspension. I'm assuming the carb will still be great next week!
 
you'll be hard pressed to beat the stock cast intake and an Edelbrock 600 on the street for both cost and performance and mileage..but you didn't want to hear that.
On the strip a bit bigger carb would be a benefit at the big end.
 
DentalDart said:
I had the 904 with 7.25 and it was great.

Just finishing up the 8.75 with 3.23 and sure grip as well as new brakes and suspension. I'm assuming the carb will still be great next week!
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Gonna run with the 7.25 (till I got the cash) to go 8.75. Thinking Hedman long tube headers, MSD ignition, aluminum radiator, Milodon 8 qt oil pan, cash,cash,cash...
 
If your going ahead and reaching for the 3.91 or 4.10 gears, then I’d definitely be going with the AirGap and the 800 cfm AVS2. You won’t have the outright “full blast” performance that you would with a double pumper carb, but you would be very close and have very good street manners. No other manifold will match the power output with a street oriented cam.
 
ir3333 said:
you'll be hard pressed to beat the stock cast intake and an Edelbrock 600 on the street for both cost and performance and mileage..but you didn't want to hear that.
On the strip a bit bigger carb would be a benefit at the big end.
Click to expand...

Ive run that combo before. If it is mildly cammed with 3.55 & down, BTDT & it’s good.
 
Kilroy Caldwell said:
Taking the stock 318 out of a 1975 Plymouth Scamp, replacing it with a 340 that has had a mild cam upgrade and ported heads. Basically going to be a street car, might occasionally drag race it, after changing to a 8- 3/4 rear end, upgrading brakes and suspension. Right now I'm leaning toward a Weiand Action + 8007WND/ Remanfactured Thermoquad 800 cfm combination or Edelbrock RPM Air Gap 7576/ Edelbrock Thunder E1826 650 cfm, but I would like to hear some other recombinations or advice, thanks.
Click to expand...

Your missing a lot of information, please try to answer these questions as best you can for a better answer;

Car weight
904-727-manual trans
Stall converter
Rear end gear ratio
Tire size
Cam size
Compression ratio
What heads /valve sizes
Flow specs
 
Garrett Ellison said:
If your going ahead and reaching for the 3.91 or 4.10 gears, then I’d definitely be going with the AirGap and the 800 cfm AVS2. You won’t have the outright “full blast” performance that you would with a double pumper carb, but you would be very close and have very good street manners. No other manifold will match the power output with a street oriented cam.
Click to expand...
Agreed except the DP comment.
I’ll take that 800 AVS II up against the Holley 750 in the street. If we are racing or the money, ether would be my choice to use.
 
Garrett Ellison said:
If your going ahead and reaching for the 3.91 or 4.10 gears, then I’d definitely be going with the AirGap and the 800 cfm AVS2. You won’t have the outright “full blast” performance that you would with a double pumper carb, but you would be very close and have very good street manners. No other manifold will match the power output with a street oriented cam.
Click to expand...
The rear end and gear is on down the line, but I'm definitely hearing, I should lean toward the air gap and function with what carb meets my purpase. Thanks for the advice, it's much appreciated, because I've only got probably this one chance to get it done. Still love the TQ, though.
 
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