Chevrolet 1973 Overhaul Manual page 504

NOTE: Refer to "Additional External Settings and Adjustments" or "Idle Stop Solenoid adjustment and
"C.E.C. Valve Adjustment", as applicable, in Section 6M (Service Manual), under carburetors
before using the following charts.
NOTE: All Idle Speeds listed are to be set with Air Conditioning OFF.
UNLESS OTHERWISE NOTIFIED:
EQUIPMENT
Transmission
L-6 250 C.I.D.
L-6 292 C.I.D.
(L-25)
Manual V-8 307 C.I.D.
(Neutral) (L-14)
V-8 350 C.I.D.
(LS-9)
V-8 454 C.I.D.
(LS-4)
L-6 250 C.I.D.
L-6 292 C.I.D.
Automatic (L-25)
(In-Drive)
V-8 307 C.I.D.
*Neutral
for H/D
V-8 350 C.I.D.
(LS-9)
V-8 454 C.I.D.
(LS-4)
(1) 1/4 turn rich from lean roll (mixture screw).
(2) With A .I.R . operating (if so equipped).
(3) Set low idle, using idle speed screw or solenoid alien head screw adjustment (with solenoid de-energized, at 450 R PM , 500 R P M
(M K IV-454).
(4) C A U T IO N : If the C.E.C. valve (solenoid) on the carburetor is used to set engine idle or is adjusted out of limits specified in the
Service Manual, decrease in engine braking may result.
* L / D Light Duty, H /D Heavy Duty — See truck identification.
OTHER ADJUSTMENTS -
Always use current specifications that agree with the "Vehicle
Emission Control Information" sticker on the vehicle.
COLUMN No. 1
(See Note Above)
Initial Curb
Idle Speed
Engine
(RPM)
Use Lean Drop Method — Except Where
1/4 Turn Rich from Lean Roll Below is
750 L/D
775 H/D
775 H/D
675 (2) H/D Calif.
950 L/D
700 H/D
920 (1) L/D
750 H/D
800 H/D
630 L/D
775 H /D *
775 H /D *
675 (2) Calif. H /D *
630 L/D
700 H /D *
620 (1)* L/D
750* H/D
625 L/D
800 H /D *
TRUCKS
COLUMN No. 2
(See Note Above)
Final Curb
Idle Speed
(RPM)
Specified as Footnote (1)
700 (3)
700 (3)
700 (3)
600 (2)(3) Calif.
900 (3) L/D
600 (3) H/D
900 (3)(1) L/D
600 H/D
700 (3) H/D
600 (3)
700 (3)*
700 (3)
600 (2)(3) Calif.
600 (3)*
600 (3)(1)* L/D
600* H/D
600 (3) L/D
700 (3) H /D *
SPECIFICATIONS 45
COLUMN No. 3
(See Note Above)
C.E.C. Valve
Engine Speed
(RPM)
(4)
1000
—
—
—
—
650
—
—
—
OVERHAUL MANUAL