1971 Chrysler CHASSIS SERVICE MANUAL
pp 0-13 thru 0-15
ENGINE OIL -- SELECTION OF
For best performance, and to provide for maximum protection of all engines for all types of operation, only those lubricants should be selected which:
[a] Conform to the requirements of the API classification "FOR SERVICE MS" or "SD"
Have the proper SAE grade number for the expected ambient temperature range (Fig 21) [Great Lakes and farther north]
Oil Viscosity Recommendations
(Where temperatures are consistently above 32F):
SAE 20W-50/20W-40/10W-40 or 10W-30
(Suitable for year long operation in many parts of the US; may be used where temperatures occasionally drop as low as -10F)
(Recommended where minimum temperatures are consistently below +10F)
(Where temperatures are consistenly above +32F)
(Where temperatures range between +32F and -10F)
If the vehicle is to be used for maximum performance service (very high speeds or very rapid acceleration), the engine requires heavier than normal lubricating oil. This is due to the high speeds, loads, and temperature of moving parts developed in these engines during this type of operation.
FOR BEST PROTECTION OF THE ENGINE UNDER THESE CONDITIONS THE HEAVIEST AVAILABLE ENGINE OIL OF MS OR SD QUALITY SHOULD BE USED THAT WILL PERMIT SATISFACTORY COLD STARTING. SAE 30 AND 40 ARE RECOMMENDED; MULTIVISCOSITY OILS SAE 20W-40 AND SAE 20W-50 MAY ALSO BE USED. IT IS ALSO RECOMMENDED THAT CHRYSLER PARTS HIGH PERFORMANCE SPERM OIL ADDITIVE (PART #3549586) BE ADDED TO THE CRANKCASE AT EVERY ENGINE OIL CHANGE IN ADDITION TO THE REGULAR CRANKCASE ENGINE OIL FILL.
MATERIALS ADDED TO ENGINE OILS
(Info about the Sperm Oil Additive, especially for the High Performance four-barrel and three two barrel carburetor engines) . . "This material may be used in these engines to aid in break-in following overhaul or piston replacement. This material may be used in any engine, but its use in high performance engines is strongly recommended".
FREQUENCY OF ENGINE OIL CHANGES
(essentially, 3-months or 4000 miles; filter every other change)
Severe Service (Frequency of Oil and Oil Filter Change)
1. Police, Taxi and Limousine Operations.
[a] Change oil every two months or 2000 miles.
[b] Change oil filter every oil change.
(Same for private owners with cold op-temps, prolonged idling, very dusty or HD trailer towing).
NOTE: for those not familiar, 1971 was one of the last years of the mechanical (non-electronic) ignition; the 426 HEMI, the 440 Six-Pack and 440 HP engines all had 9.7:1 compression or a little better (as rated). Other engines were 225 Slant-6, 318-2V, 340-4V, 360-2V, 383-2V & 4V, 440-4V.
1972 saw the downrated HP figures, lowered compressions (already on some engines), etc, etc, as to emissions controls.