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Engine Information for '61-'71 Dodge Trucks
Engine Resources
These resources are pages on this site that include specific information about the topics of a LA-318 Engine Rebuild, Tuning Tips, Engine Swaps, Early Hemi Engines and Exhaust System Recommendations. This information was taken from various sources which are listed at the top of each page. Click the text links above or at the top of this page to view these resources.

Original Equipment Engines
For the production run from 1961-1971, there were a variety of engines that the engineers at Chrysler deemed suitable for Sweptline Era Trucks. From the tried and true Slant-Six to the mighty 383 Big-Block in later years, Mopar gave their trucks a good selection of reliable powerplants in this time period.

Below is a table from the `65 service manual adapted for the entire Sweptline Era. The 383 didn't come into the market until `67 and the same is true for the LA-318. Further below is some interesting notation for the different "grades" of engines available based on a 1-3 scale for each displacement. Higher grade numbers generally denoted tougher parts. The 361 was a small displacement B-series big-block motor.

Engine Specs - Engine Usage `61-`71 Dodge Trucks
Six-Cylinder Engines V-8 Engines
Models Standard Extra Standard* Extra Extra
A-100's (all `64-`70) 225-1 170- 273 (318)**-
D-100, D-200, W-100, W-200225-1 170318-1 383 (`67-`71)426W^
D-300 225-1 -318-1 --
W-300 225-2- 318-3- -
WM-300 (`61-`67 USA) 251-3 -- --
D-400 225-2- 318-3318-3 -
D-500 225-2- 318-3318-3 361-2
W-500 225-2- 318-3318-3 -
D-600 -- 318-3318-3 361-2
D-700 -- 361-3- -
* Standard where Six-Cylinder engine is not offered.
** 273 available `65-`66, LA-318 `67-`70
^ 426 Wedge available as part of the Custom Sport Special Package (`64-`67).

Engine Code Notation
Six-Cyl.V-8
170Standard Engine-OHV 318-1Standard Engine
225-1Standard Engine-OHV 318-2Semi-Premium Engine
225-2Premium Engine-OHV318-3 Full Premium Engine
251-3Standard Engine-in line 361-2Full Premium Engine Heavy Duty
361-3 Full Premium Engine Modified Torque

The tables above would probably reflect the same applications for later engines, except that the 383 was added as an option to the `67-up trucks and the LA-318 engine replaced the Polysphere A-318 in `67 as well.

Six Cylinder Engines
Image from '65 Dodge Truck Service Manual
While the 251 flathead-six was only installed in military style WM-300 Power Wagons, Sweptline Era pickups were fitted with versions of the new Slant-Six. Nonetheless, many of the flathead sixes are still running strong in many of the earlier Dodge Trucks out there.

Quick Specs: 251-3 L-Head Six
Firing Order1-5-3-6-2-4
Bore3.437
Stroke4.50
Displacement250.6
Compression7.0:1
Basic Timing5 BTDC
Horsepower125 @ 3600 rpm
Torque216 @ 1600 rpm

1961 brought with it the introduction of the Slant-Six in the newly re-engineered trucks. The standard engine from `61 to `71 in light duty D-100's was the 225cid motor, however the 170cid Slant-six could also be had if desired. An interesting application of the 170 Slant-Six in a Sweptline Era truck is the Sweptline Special truck marketed in 1971 only. The purpose of this low-line, shortbox truck was to target small business or fleet buyers with a low priced, economical truck. It was touted as one of the lowest priced trucks of its class when compared to the offerings by F*&d and Ch#%y.

Quick Specs: 170-1 Slant-Six
Firing Order1-5-3-6-2-4
Bore3.41
Stroke3.125
Displacement170
Compression8.5:1
Basic Timing2.5 BTDC
Horsepower101 @ 4000 rpm
Torque145 @ 1600 rpm

Quick Specs: 225-1, 225-2 Slant-Six
Firing Order1-5-3-6-2-4
Bore3.41
Stroke4.125
Displacement224.43
Compression8.4:1
Basic Timing2.5 BTDC
Horsepower140 @ 3900 rpm
Torque215 @ 1600 rpm


V-8 Engines
Both small and big block V-8's were installed in Sweptline Era trucks. These engines include the Polysphere and LA-series 318 engines as well as the 361 and later the 383 big block engines. Small block LA-273 engines were available in the A-100 from `64-`67; in `67 the LA-318 replaced the optional 273 offering. Custom Sport Special Trucks offered an optional 426 Wedge motor but the rarity of this option is only worth short mention relative to the other V-8 engines that were available.

Small Block Motors
Image from How To Rebuild Small Block Mopar Engines
The Polysphere (or Wideblock) 318
The Polysphere A-series small block is commonly known as the "Wideblock" engine because it has such a wide top end in comparison to more modern small blocks. It was a direct decendant of the Early Hemi, and likewise had hemispherical/polysphere combustion chambers. The rocker arms were also very much like those of the Early Hemi. There are many differences between the Polysphere "A" engine and the LA-series small blocks that came first in 1964. Most notably, the "LA" engines were of a thinner block wall casting and had a true wedge head design. Some parts will interchange between the two motors, but many parts are engine specific and will not interchange. The easy way to spot a Polysphere 318 is by the valve covers, they have ripples along the exhaust side of the cylinder head and are attached with two bolts along the top of the cover.
Quick Specs: "A" 318-1 `61-`66 (Polysphere)
Firing Order1-8-4-3-6-5-7-2
Bore3.91
Stroke3.312
Displacement318
Compression8.25:1 (7.50:1)*
Basic Timing10 BTDC (12 BTDC)*
Horsepower200 @ 3900 rpm
Torque286 @ 2400 rpm
*Values for the 318-3 Engine.
Looking for high performance parts for your Wideblock or Polysphere engine? Although not much is available, there are cams and intake manifolds that are still being made for your early "A" motor. Here's a rundown: Unfortunately, high performance parts for these engines are scarce but a slow growing aftermarket is gaining ground. Early versions of these engines had a dual quad intake available from the factory which was not installed on the trucks. Sometimes you can find these dual-quad manifolds at swap meets, etc. Headers are available from the aftermarket as an assembly, and two companies make the flanges and sell kits for making a set. More information:

For a complete set of headers for your Polysphere engine in a `61-`71 Dodge Truck, call Harold Johnson of Spitfire Headers in Arkansas at (501) 474-0120. Special thanks to Bill Pate for this tidbit of information (Bill says the Headers are a great fit).

Stan's Headers
4715 Auburn Way North
Auburn, WA 98002
(206) 854-5310 or (206) 850-1835
http://www.stans-headers.com/

Headers by ED
P.O. Box 7494
Minneapolis, MN 55407
(612) 729-2802
http://www.headersbyed.com

The Polyspherical Engine Association
The Polyspherical Engine Association is dedicated to the preservation and ownership of Early A-series V8 engines such as the 277, 301 and 318. Check out their Website for further information on parts resources, links, and other technical information.
The Polyspherical Engine Association
Bob Asay
353 Prospectors Lane
Billings, MT 59105
E-mail: belvedere30@hotmail.com
http://www.geocities.com/MotorCity/Track/4164/

LA-Series Engines
Continuing as a production engine in today's fleet of Dodge Trucks (although quite revamped), the LA-series engine is still the choice for a rock-solid V-8 engine. The designation "LA" stands for "low-A", in regards to the hood height available. You can also interpret the L and A to mean the later-A engine. In either case, the first LA engine was the 273 which hit the market in `64. A-100's also reached the consumers in this year; however, the 273 was not an option for these vehicles until `65. In `67 the LA-318 was created from the same block specs as the 273 with a larger bore which created a larger compression chamber.

Quick Specs: LA-273 V8
Firing Order1-8-4-3-6-5-7-2
Bore3.625
Stroke3.312
Displacement274.04
Compression8.8:1
Basic Timing5 BTDC
Horsepower180 @ 4200 rpm
Torque260 @ 1600 rpm

Quick Specs: LA-318 V8
Firing Order1-8-4-3-6-5-7-2
Bore3.91
Stroke3.312
Displacement317.95
Compression8.50:1
Basic Timing10 BTDC
Horsepower210 @ 4000 rpm
Torque280 @ 2400 rpm

In 1968 the 340 engine was born to the musclecar era of Mopar vehicles while in 1971 the 360 followed. Neither of these LA-series engines were available in `61-`71 Sweptline Era Trucks.

Big Block Engines
First available in `67 as an option for D and W-series half, 3/4 and one ton trucks, the 383 was the only engine not modified from the car version to fit truck duty. Slant-Six and Small block truck engines were different from car versions as they generally had tougher bearings and forged cranks as well as modified compression for higher torque. Engineers at Chrysler deemed that the 383 did not need enhancements such as these because it already had the torque and horsepower to handle the loads it would have to carry in the light-duty truck application. Surprisingly, the heavier duty Dodge Trucks from the same era, such as the W-300 and D-300 to D-700 trucks, had only the 361-2 and 361-3 B-series engines to choose from as optional over the Slant-Six. The 383 was not an option for these trucks. Nonetheless, the 361 engine was available in all of the larger trucks from `61 to `71. Of the optional engines available throughout `61-`71, the 426 Wedge which was available in the Custom Sport Special package is probably the most interesting. If the 426 was ordered for one of these trucks, dual exhaust and a custom instrument cluster with tachometer were required by the factory.

Quick Specs: B-383 V8
Firing Order1-8-4-3-6-5-7-2
Bore4.25
Stroke3.38
Displacement383.59
Compression9.2:1
Basic Timing10 BTDC
Horsepower258 @ 4400 rpm
Torque375 @ 2800 rpm

Quick Specs: 426 Wedge V8 (CSS Only)
Firing Order1-8-4-3-6-5-7-2
Bore4.25
Stroke3.75
Displacement425.58
Compression10.3:1
Basic Timing?? BTDC
Horsepower365 @ 4800 rpm
Torque470 @ 3200 rpm

Torque Specs & Images
Engine Bolt Torque Specifications (in ft-lbs)
EngineHeadsRods MainsBalancerFlywheel IntakeExh. Manifold
198654585 -5510 10
225654585 -5510 10
251-L6704585 135602520
A-318854585 135553025
LA-318704585 135553525
B-383704585 135555030
B-413704585 135555030
All values are in ft-lbs

Cylinder Head Torque Specs for Truck Engines
EngineTorque SpecTightening Sequence Images
251 L-Head Six70 ft-lbs251_tq.jpg
170-225 Slant Six65 ft-lbsslant6_tq.jpg
Polysphere 31885 ft-lbspolyv8_tq.jpg
273-318 Small Block (LA-engine)70 ft-lbssmallv8_tq.jpg
Big Block Engines70 ft-lbsbigv8_tq.jpg

General Engine Rebuild Info
When building up your Dodge Truck, you will undoubtedly want to improve on the horsepower figures. When doing so, there are many considerations that you will want to explore before you sink loads of cash into the this part of your project. Also, you will need to search for suitable parts to achieve your goal. In working with these trucks, searching for hours on end for the right parts and considering all the factors of the buildup of my own engine I have compiled some helpful hints that can save you some time and money.

To get started, evaluate what you have currently. That is, think about the engine you have now. Is it rebuildable? Are parts readily avaliable for it? Also think about how much money you have. How much can I feasibly spend on my engine and get the performance I am looking for? Can I rebuild it myself? Do I have the tools and facilities to do so? Next, think about the purpose for the engine. Hauling and towing? Racing? Daily driver? Finally, think about the engine options available. Small block or big block? Original or custom? It is important to consider all of these aspects in order to maximize the end result.

You may want to catch up on some Auto Mechanics 101 if you are unfamiliar with how an engine works. Books are usually available at the library which describe engine basics. Or, consider an engine rebuilding manual especially if you will be performing the rebuild yourself. They come in real handy, especially for swaps and other commonly overlooked problems that one may encounter. You can find these books at bookstores and auto parts stores. Make sure to purchase the book that matches what engine you are rebuilding. These are much easier to use and describe the brand specific quirks much more completely than do generic books.

Learn more about the inner workings of an automobile at The Autoshop Online Website.

Interested in a list of recommended engine rebuild manuals and other Dodge Truck Enthusiast books? Check out the Books Page, located on this site.

Once you have decided which way you plan to go, check into reputable parts stores and engine rebuilders near you. Compare the prices and see if you can find out from friends or fellow hot rodders which shops are reputable and friendly. Also ask if they are able to perform the necessary modifications you want and sell the parts to do so.

At this point, you have a choice to make as far as what kind of truck your engine will power. If the truck is to be resto correct, then you probably aren't interested in a great deal of high performance modifications. For this case you can do some research into what the original engine specifications were, then perform a rebuild geared to those specs.

If the truck is going to be a reliable daily driver, race or show vehicle, a high performance focus may be what you're looking for. Check out the High Performance Page elsewhere on this Website.

In both cases, research into some Books and Magazines will help you determine what to aim for in a rebuild.

Electronic Ignition
Image from actual package.
Mopar Performance offers an Electronic Ignition Conversion Kit for small and big-block engines. This kit includes everything needed to exchange the inefficient points distributor over to the more modern electronic breakerless type which Chrysler engineers introduced in 1972. An electronic control unit, new breakerless distributor and all necessary wiring is included with complete instructions.

This is one of the few high performance upgrades that has no significant drawbacks. With the exception of finding a suitable location to mount the ECU, the performance and drivability gains largely justify the price and trouble required to perform the swap.

Be sure to check the Parts Sources page on this site to find out where you can get the best parts and service for your Dodge Truck.

Engine Resources
| LA-318 Rebuild Specifics | Tuning Resources | Exhaust Suggestions |
| Engine Swaps | Early Hemis |


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