Mopar 440 Idle Speed: Idle and RPM for Automatic or Manual
Many owners wonder what their Mopar 440 idle speed or RPM should be set at or what was set by the factory when new.
The following are the Mopar 440 High-Performance idle speeds for each year:
- 1967: 650 RPM (auto or manual)
- 1968: 650 RPM (auto or manual)
- 1969: 650 RPM (auto) 700 RPM (manual)
- 1970: 800 RPM (auto) 900 RPM (manual)
- 1971: 900 RPM (auto or manual)
- 1972: 900 RPM (auto or manual) 800 (manual/California)
- 1973: 800 RPM (auto or manual)
- 1974: 800 RPM (auto)
The following are the standard Mopar 440 idle speeds for each year:
- 1966: 500 RPM (auto or manual/without CAP)
- 1966: 600 RPM (auto/w CAP) 650 RPM (manual/w CAP)
- 1967: 650 RPM (auto or manual)
- 1968: 550 RPM (auto)
- 1969: 600 RPM (auto)
- 1970: 650 RPM (auto)
- 1971: 750 RPM (auto)
- 1972: 750 RPM (auto) 700 RPM (auto/California)
- 1973: 700 RPM (auto)
- 1974: 750 RPM (auto)
Keep reading for more details and why the RPMs increased over the years. In addition, this article will explain every year’s fast idle RPM, California specs and list the carburetor numbers.
Mopar 440 Idle Speed
Idle speeds have changed over the years due to the Cleaner Air Package (CAP), Cleaner Air System (CAS) and Evaporation Control System (E.C.S.).
These systems were designed to reduce engine emissions. One of the ways to accomplish this was increasing the curb and fast idle speeds.
C.A.S. was introduced first. C.A.P. later became C.A.S. Then E.C.S. was introduced in 1970 for California cars. In 1971 all the Chrysler engines came equipped with C.A.S. and E.C.S.
Obviously if your cam or engine has been modified in any way, these idle specs may not pertain to you. Either way, it’s interesting to see how things were back then and how they changed during the 440 engine’s production.
This article will cover the “muscle car” years, 1966-1974. Both standard and high-performance 440 engines are both included.
440 High-Performance Idle Speed and RPM Specs
1967 Idle Speed: 440 High-Performance (H.P.) Without CAP
The following idle specs are for the Carter AFB carburetors.
Manual Transmission (AFB-4326S)
- Curb Idle Speed: 650 RPM
- Curb Idle Speed (with AC on): 650 RPM
- Fast Idle Speed: 800**
Automatic Transmission (AFB-4327S)
- Curb Idle Speed: 650 RPM
- Curb Idle Speed (with AC on): 650 RPM
- Fast Idle Speed: 700 RPM**
** Speed set on second highest step of the fast idle cam.
1967 Idle Speed: 440 High-Performance (H.P.) With CAP
The following idle specs are for the Carter AFB carburetors with the cleaner air package.
Manual Transmission (AFB-4328S)
- Curb Idle Speed: 650 RPM
- Curb Idle Speed (with AC on): 650 RPM
- Fast Idle Speed: 1,600**
Automatic Transmission (AFB-4329S)
- Curb Idle Speed: 650 RPM
- Curb Idle Speed (with AC on): 650 RPM
- Fast Idle Speed: 1,400 RPM**
** Speed set on second highest step of the fast idle cam.
1968 Idle Speed: 440 High-Performance (H.P.)
The following idle specs are for the H.P. engine with the Carter AVS Carburetor.
Manual Transmission (4428S)
- Curb Idle Speed: 650 RPM
- Fast Idle Speed: 1,600*
Automatic Transmission (4429S)
- Curb Idle Speed: 650 RPM
- Fast Idle Speed: 1,400 RPM*
* After approximately 500 miles (if necessary).
1969 Idle Speed: 440 H.P.
The following specs are for the Carter AVS carburetors.
Manual (AVS-4617S)
- Curb Idle Speed: 700 RPM
- Fast Idle Speed: 1,700 RPM*
Automatic Transmission (AVS-4618S/4640S)
- Curb Idle Speed: 650 RPM
- Fast Idle Speed: 1,700 RPM*
* After approximately 500 miles (if necessary)
1970 Idle Speed: 440 H.P.
Manual Transmission with C.A.S. (AVS-4737S)
- Curb Idle Speed: 900 RPM
- Fast Idle Speed: 2,000 RPM*
Automatic Transmission with C.A.S. (AVS-4738S/Without AC)
- Curb Idle Speed: 800 RPM
- Fast Idle Speed: 1,800 RPM*
Automatic Transmission with C.A.S. (AVS-4741S/With AC)
- Curb Idle Speed: 800 RPM
- Fast Idle Speed: 1,800 RPM*
Manual Transmission with E.C.S. (AVS-4739S)
- Curb Idle Speed: 900 RPM
- Fast Idle Speed: 2,000 RPM*
Automatic Transmission with E.C.S. (AVS-4740S)
- Curb Idle Speed: 800 RPM
- Fast Idle Speed: 1,800 RPM*
* After approximately 500 miles (if necessary)
1971 Idle Speed and RPM Specs
In 1971 all Chrysler cars were equipped with the evaporation control system (E.C.S.). Therefore, there are no differences between CAS and ECS liked in 1970.
Manual Transmission (AVS-4967S)
- Curb Idle Speed: 900 RPM
- Fast Idle Speed: 2,100 RPM*
Automatic Transmission (AVS-4968S)
- Curb Idle Speed: 900 RPM
- Fast Idle Speed: 1,800 RPM*
* After approximately 500 miles (if necessary)
1972 Idle Speed: 440 High-Performance
The following idle specs are for the Holley model 4160 series carburetors.
Manual Transmission (R-6252A)
- Curb Idle Speed: 900 RPM
- Fast Idle Speed (2nd Step): 1,800 RPM
Automatic Transmission (R-6253A)
- Curb Idle Speed: 900 RPM
- Fast Idle Speed (2nd Step): 1,600 RPM
Manual Transmission (R-6254A)
- Curb Idle Speed: 900 RPM
- Fast Idle Speed (2nd Step): 1,800 RPM
Automatic Transmission (R-6255A)
- Curb Idle Speed: 900 RPM
- Fast Idle Speed (2nd Step): 1,600 RPM
Manual Transmission (R-6256A) California Specs
- Curb Idle Speed: 800 RPM
- Fast Idle Speed (2nd Step): 2,000 RPM
Automatic Transmission (R-6257A) California Specs
- Curb Idle Speed: 900 RPM
- Fast Idle Speed (2nd Step): 1,800 RPM
1973 Idle Speed: 440 High-Performance
The following idle specs are for the Carter Thermo-Quad carburetors.
Automatic Transmission (TQ-6324S)
- Curb Idle Speed: 800 RPM
- Fast Idle Speed (after 500 miles): 1,700 RPM
Automatic Transmission (TQ-6411S) California Specs
- Curb Idle Speed: 800 RPM
- Fast Idle Speed (after 500 miles): 1,700 RPM
1974 Idle Speed: 440 High-Performance
The following idle specs are for the Carter Thermo-Quad carburetors.
Automatic Transmission (TQ-6462S)
- Curb Idle Speed: 800 RPM
- Fast Idle Speed (after 500 miles): 1,700 RPM
Automatic Transmission (TQ-6463S) California Specs
- Curb Idle Speed: 800 RPM
- Fast Idle Speed (after 500 miles): 1,700 RPM
Other Idle Speed Articles:
- I wrote a separate article for the 6-Pack which you can check out here, 440 Six Pack Idle Speed.
- Find out how the Hemi idle speeds compared in my article 426 Hemi Idle Speed.
440 Idle Speed: Standard Engine
In 1966, the first year of the Mopar 440 engine, there was only a standard 440 without the high-performance engine.
1966 Idle Speed: 440 Without CAP
The following idle specs are for the Carter AFB carburetors.
Manual Transmission (AFB-4130S)
- Curb Idle Speed: 500 RPM
- Curb Idle Speed (with AC on): 500 RPM
- Fast Idle Speed: 700 RPM
Automatic Transmission (AFB-4131S)
- Curb Idle Speed: 500 RPM
- Curb Idle Speed (with AC on): 500 RPM
- Fast Idle Speed: 700 RPM
1966 Idle Speed: 440 With CAP
The following idle specs are for the Carter AFB carburetors with the cleaner air package.
Manual Transmission (AFB-4136S)
- Curb Idle Speed: 650 RPM
- Curb Idle Speed (with AC on): 650 RPM
- Fast Idle Speed: 1,500 RPM
Automatic Transmission (AFB-4137S)
- Curb Idle Speed: 600 RPM
- Curb Idle Speed (with AC on): 600 RPM
- Fast Idle Speed: 1,500 RPM
1967 Idle Speed: 440 With CAP
The following idle specs are for the Carter AFB carburetors with the cleaner air package.
Manual Transmission (AFB-4311S)
- Curb Idle Speed: 650 RPM
- Curb Idle Speed (with AC on): 650 RPM
- Fast Idle Speed: 1,400**
Automatic Transmission (AFB-4312S)
- Curb Idle Speed: 650 RPM
- Curb Idle Speed (with AC on): 650 RPM
- Fast Idle Speed: 1,400 RPM**
** Speed set on second highest step of the fast idle cam.
1968 Idle Speed: 440
The following idle specs are for the Holley 4160 4-barrel downdraft carburetor.
Automatic Transmission (R-3918A)
- Curb Idle Speed: 550 RPM
- Curb Idle Speed (with AC on): 550 RPM
- Fast Idle Speed (No. 2 Step): 700 RPM
1969 Idle Speed: 440
The following idle specs are for the Holley 4160 4-barrel downdraft carburetor.
Automatic Transmission (R-4166A)
- Curb Idle Speed: 600 RPM
- Fast Idle Speed (No. 2 Step): 1,400 RPM
1970 Idle Speed: 440
The following idle specs are for the Holley 4160 4-barrel downdraft carburetor.
Automatic Transmission (R-4366A) C.A.S.
- Curb Idle Speed: 650 RPM
- Fast Idle Speed (No. 2 Step): 1,600 RPM
Automatic Transmission (R-4360A) E.C.S.
- Curb Idle Speed: 650 RPM
- Fast Idle Speed (No. 2 Step): 1,600 RPM
1971 Idle Speed: 440
In 1971 all Chrysler engines came equipped with C.A.S. and E.C.S.
The following idle specs are for the Carter AVS 4-Barrel carburetor.
Automatic Transmission (AVS-4966S)
- Curb Idle Speed: 750 RPM
- Fast Idle Speed: 1,800 RPM*
* After approximately 500 miles (if necessary)
1972 Idle Speed: 440
The following idle specs are for the Holley Model 4160 Series 4-Barrel carburetors.
Automatic Transmission (R-6160A)
- Curb Idle Speed: 750 RPM
- Fast Idle Speed (2nd Step): 1,600 RPM
Automatic Transmission (R-6290A) California Specs
- Curb Idle Speed: 700 RPM
- Fast Idle Speed (2nd Step): 1,500 RPM
1973 Idle Speed: 440
The following idle specs are for the Carter Thermo-Quad carburetors.
Automatic Transmission (TQ-6322S)
- Curb Idle Speed: 700 RPM
- Fast Idle Speed (after 500 miles): 1,700 RPM
Automatic Transmission (TQ-6410S) California Specs
- Curb Idle Speed: 700 RPM
- Fast Idle Speed (after 500 miles): 1,700 RPM
1974 Idle Speed: 440
The following idle specs are for the Carter Thermo-Quad carburetors.
Automatic Transmission (TQ-6460S)
- Curb Idle Speed: 750 RPM
- Fast Idle Speed (after 500 miles): 1,700 RPM
Automatic Transmission (TQ-6461S) California Specs
- Curb Idle Speed: 750 RPM
- Fast Idle Speed (after 500 miles): 1,700 RPM
If you have any questions or if you have more information you’d like to contribute, send us an email found on our contact page.
I learned the hard way adjusting the idle speed on my 440 Six-Pack engine 39 years ago. I had a high-performance cam which increased the idle speed. I’ve been researching Mopars and the 440 engines for approximately 40 years. My research includes personal experience, books, manuals, articles, magazines, webinars, live events and videos.
Read More Mopar Engine Articles!
Mopar 440 Compression Ratio (All Years)
Article Resources
- Plymouth, Chrysler and Dodge Service Manuals: 1966-1971
- Wikipedia: Chrysler B Engine
- Google Books: Chrysler Engines 1922-1998
- Google books: The Definitive Plymouth Barracuda and Dodge Challenger Guide: 1970-1974