Cop Car Information
Below is information on M-body Diplomat and Gran Fury police cars. Chrysler LeBarons were also used in police service for the 1981 model year only.Visible clues that an M-body was formerly a police car:
Under Hood Clues:
- An "S" or "L" in the VIN#:
This almost always means "police package". A few private owners may have ordered these engine options, but they are almost exclusively seen on police cars. However, some municipalities did use police cars with other engine options, i.e. ordinary duty 4bbl 318s and even 2bbl 318s.
- "S" In the VIN # indicates the heavy duty 4bbl 318.
- "L" In the VIN # indicates the heavy duty 2bbl 318.
- Tires: At this point, tires have probably been switched long ago. However, police cars had wider performance tires. They usually came with Goodyear F32 P215/70 R15 tires.
- Wheels: Police cars came with 6 slotted 15x7" steel wheels with 4.5" bolt circles. Hub caps were usually the small "dog dish" type that snapped onto the center of the wheels.
- Brakes: The brakes will have 11" drums on the rear. Civilian versions) are 10". The only exception to this are taxi packages, which will also have 11" drums.
Other Visible Clues:
- Look for an ID tag on the top of the left hand inner fender which is held in place by two screws. On the plate is all of the body, trim, paint color, style and manufacturing info. For model years prior to 1984, Chrysler, Dodge and Plymouth used the "A38" designation for police packages. From 1984 forward Chrysler changed the code to "AHB". The code should be in the second or third line of information. A38 was dropped after 1983, it was used on the Diplomat/Fury for the those models with the pursuit six cylinder. Also look for engine codes E48 or ELE – HD 318 4bbl, and E45 or ELD HD 318 2bbl.
- 49-state smog certification. If it comes with "California Smog Certification", it's a civilian car.
- 4 BBL Carburetor, 2 Core Radiator, heavy duty transmission cooler in front of the radiator, power-steering cooler (finned fluid line), heavy duty alternator (noticeably larger than the civilian version), NO computer mounted on the air cleaner - it’s under the dash board. Also look for a roughly 6" tall oil filler extension tube with a pull-off cap that screws into the valve cover oil fill hole on the passenger side.
- There may be heavy wires visible which have been cut/capped off
Other police car specifications not found in civilian M-bodies:
- A REAR SWAY BAR. This is probably the easiest way to spot a cop car
- Police cars have single-diameter rear axle tubes. Civilian M-bodies have the lighter-duty rear axle tubes that narrow in diameter as they get close to the differential.
- No vinyl roof. However, some federal service units were equipped with vinyl roofs
- Dash-mounted manual oil-pressure gauge in a special adapter plate
- 125 mph "calibration guaranteed" or "certified" speedometer
- Miscellaneous holes and cut-outs for spotlights, antennas, shotguns, passenger cages, computers, dashboard lights and pads, pushbars, sirens, etc. Body holes may or may not have been filled in with bondo.
- On some cars, plates are welded to the rear door jambs for the striker post. Apparently to keep prisoners from kicking the doors open.
- Welded reinforcements on front fender braces
- Earlier (pre 1984?) cars will have 727 transmissions. The 727 was discontinued as standard around 1983. However it was available as a special order throughout end of the production run in 1989.
- Dome light may not function when doors are opened, or there may be extra interior lights
- Push bars on the front bumper
- The engine should be a 318 with 360 heads - special kolene cleaned with special high silichrome-1 temp steel intake valves
- Four barrel intake manifold (this is not an absolute, since 2 barrel cop cars were also produced
- Heavy duty exhaust manifolds
- Double roller timing chain,
- Hyperutectic pistons with special piston-to-block clearances (allowable by use of the hyperutectic pistons),
- Heavy duty chrome plated oil rings,
- Forged steel connecting rods (actually, all Chrysler civilian and cop car engines had forged rods, including the Slant 6)
- Heavy duty valve springs
- High strength rocker arms
- High temp cylinder head cover gaskets
- High temp valve seals and shields
- Lubrite treated camshaft. 4bbl and 2BBL flat tappet and roller versions usually had .373"intake/.400" exhaust lift with 240/240 advertised duration. Specifications were the same as the civilian versions.
- Nimonic exhaust valves
- Heavy duty water pump
- Windage tray
- Through 1983 2bbl cars had the 904, and 4 bbl cars got the 727. Beginning 1984, 2bbl cars got the A998, and 4bbl cars got the A999. As mentioned, the 727 was apparently available as a special order throughout the end of the production run in 1989. A 1989 Pymouth Gran Fury 2bbl police car with a factory installed 727 was observed in a Clarksville, MD junkyard.
- Some police cars may have 1st gear locked out (i.e. no manual downshifting to first gear - only automatic downshifting). This was done by Chrysler to prevent police personnel from slamming down into first to slow down quickly after a high speed chase and to prevent them from doing the same for quicker acceleration thus over-revving the engine. The lock-out may have been removed when the car was prepped for sale to the civilian market.
Rear Axle and Differential:
- Police cars came with 5-leaf rear springs. Civilian models usually had 4-leaves unless they were special ordered
- Note that the 5-leaf setup takes a different lower ISO-CLAMP than the civilian setup. This is the bottom half of the ISO-CLAMP setup that holds the lower rubber pad against the bottom of the spring. The civilian clamp height is 3" from top to bottom. The HD or "cop car" clamp height is 3.25" from top to bottom to accomodate the fifth leaf.
- Police cars came with a heavier front sway bar than civilian versions.
- Police cars came with a rear sway bar. Civilian versions usually did not.
- Police cars came with different shock plates to accomodate the rear sway bar. Civilian versions usually did not.
- It has been rumored, but never comfirmed that some police cars may also have had solid cast iron K-member isolators rather than the civilian rubber ones. As far as it is known, there were no M-bodies produced from the factory with solid isolators. However, they were once available from Mopar Performance, and police departments could have retrofitted them on their own. The solid isolators is made the ride somewhat harsher than their civilian counterparts, but greatly improved handling by eliminating movement between the unibody and the K-member.
Good Model Years for Police Cars:
- Police cars have the 8 1/4" differential. All 8 1/4" rears will have the 2.94 gears except 1983 to 1985 2bbl police cars which came with 2.24 gears unless special ordered with 2.94. Some 8 1/4" rears were ordered with Sure Grip (limited slip), which was a separate option. See How to Identify Sure-Grip And Gear Ratio. Civilian M-bodies have the 7 1/4" rear ends without Sure-grip and much lower gear ratios - usually around 2.26:1.
First of all, realize that all Dips/GFs were a pretty similar run from 1980 right up to 1989. Pre-1980 models (starting in 1977 per Mike) had significantly different sheet metal, but still the same underpinnings. The A38 police package was not available on 1980 M Bodies. F Body Aspen and Volare were the mid-size police cars. 1981 was the first year for an M Body A38, and the 360 was no longer available (except in vans and trucks). No 360s were ever factory installed in A38/AHB M Bodies. But, the 360 debates and urban legends will live on.... With that in mind, the best years for police Dips/GF’s are:
- 1984 - Considered by some to be the best as they had the best performance, per those who drove them in actual duty.
- 1988 and 1989 - From 1988 on, the front K-frame was finally beefed up. Previous years tended to bend the upper towers inward, needing constant adjustments to the camber and toe. Eventually shims had to be installed to give more adjustment, as none was left. (note: This was only a problem with police cars due to the extreme duty that they saw. Civilian models seemed to have been ok.
- Special note: Chrysler changed carburetor manufacturers and began using the "Quadrajet/Chevy" type carburetors in 1985.
- Dodge, Plymouth & Chrysler Police Cars 1979-1994 - Sanow & Bellah
- Additional information provided by CopCar George Chang, Tom, Steve, Malcolm, Mike, Adam, Norm and other Farley board members