Duffy Armitage, a fellow enthusiast and owner of a '70 D-100 with the 392 Hemi installed, is quite familiar with the Early Hemi swap. He generously detailed many fine points of this swap expressly for this Website, and his valuable information is the basis for this page. See also the more generalized Engine Swaps page for additional information on swapping engines into these trucks.
In regards to `61-`71 Dodge Trucks, the swap is not a difficult one to achieve with proper research, a little ingenuity and the correct parts to adapt a more modern transmission. As Duffy Armitage puts it, "The swap to an Early Hemi is really a straight forward and simple one." In fact, Duffy's information also applies to the 331 and 354 Hemis along with the 392 which was his engine of choice. Read on and find out what is necessary to complete this unique swap into your `61-`71 Dodge Truck.
See also Dave DeGan's Hemi Page for more information on adapting the A-833 transmission.
The adapter makes the engine/tranny combo 5/8" longer than a stock 318 and 727 automatic, but the difference is slight. Everything should fit the OEM automatic transmission crossmember in these trucks. If your truck has a manual transmission, modifications such as a custom crossmember or installing a used automatic crossmember may be necessary. Most later (`68-`71) trucks have both crossmembers and can be easily adapted to the new combo with little or no modifications. In either case there are two ways to adjust the combo to fit like the "intended" engine/tranny setup. Simply bolt the engine mounts to the back of the engine mount bosses to make up for the extended 5/8" (due to the adapter) or bolt in the combo as per normal and use the adjustment slot in the stock automatic tranny crossmember. Either way should work, both with the truck and driveline.
The Early Hemi is balanced much like pre-`71 Mopar small and big block motors. For the automatic, the hot ticket is to use the 340 or 383 Magnum torque converter. A B&M flexplate will facilitate the connection to the 8-bolt crank flange, which is just like that of the 426 Hemi.
It is possible to use the same driveline if:
A.) you have the passenger car automatic or 4-speed and
B.) you have the automatic truck driveline.
Most driveline or tranny shops can inexpensively modify a driveline for you in the event that you need to make some changes to your existing setup.
A later (`68-`71) column will easily adapt to your automatic linkages, and includes the shifter as an integral part of the assembly. As for linkages, it is recommended that the OEM later truck linkages also be used. Kickdown parts can be had from a C-body Mopar with some modifications to the length of the rods down to the tranny and over the intake manifold. If you're planning on a dual quad setup, simply modify the linkages from the C-body. Aftermarket dual quad linkages may work, but are known to bind within normal use.
Positive Crankcase Ventilation - In order to get rid of the road draft tube and install a PCV system, you can use parts from a `60's small block Mopar engine. The basis for this is the grommet from the passenger side small block valve cover. Place this part in the road draft tube hole (on lifter valley pan), then add your PCV valve and grommet to the grommet in the valley pan.
Alternator - Duffy used the triangular bracket from the small block application along with the adjustable slotted bar from a pre-`62 Mopar generator setup. This arrangement works well with the stock water pump. For other pumps, in particular the Ch#*y Big Block variety, it is recommended to use the appropriate adapter from the companies that made the kit to adapt the pump.
Pumps - it is possible to use the stock water pump, but for better efficiency you may want to look into the parts available from various Early Hemi outfitters. They can offer a variety of pump solutions, pulleys and brackets to prepare the driven accessories of the vehicle. This includes the fuel pump and even the power steering pump if needed. In most cases, the brackets and pulleys are the most difficult part of making these items work with the Early Hemi engine. It is possible to use an electric fuel pump in place of the mechanical pump. Adapters are also available for the more common small block Mopar fuel pump which properly align the pump arm to the Hemi fuel pump eccentric.
Pulleys and Balancers - The stock Hemi balancer or a new balancer for the same can be used. Pre-`71 B-engine balancers will also fit but must be re-indexed with the proper timing marks. If the stock damper is used, it can be shimmed with a 1/16" plate to accept any pre-`71 crank pulley originally used with a balancer. This will properly align the crank pulley with the rest of the driven accessories.
Cooling - A `69 C-body big block radiator was used in Duffy's D-100, as well as an aftermarket transmission cooler. Most Mopar radiators have a 4-bolt mounting method, and are for the most part interchangable. The toughest part is matching up the hose outlets. The `69 C-body radiator worked well under these conditions, along with the aftermarket tranny cooler.
Oiling System Items - Both the passenger car Early Hemi oil pans and the larger truck pans will work well this application. Armitage also recommends a remote oil filter setup, which acomplishes two things. First, it does away with the annoying canister type filter on these engines, and it makes the filter more accessible for maintainence purposes.
Ignition - The stock dual point distibutor that is found on most Early Hemis works with this swap. Some tranny adapter suppliers also carry adapters for the later small block distributor, which would allow for endless posibblities in regards to ignition systems. The recommended setup for best performance and low maintenance is, of course, the Mopar Electronic Ignition Conversion Kit.
See also the Exhaust Suggestions Page on this site for further information on a high quality exhaust system.
The Early Hemi Registry
Tons of info on all Early Chrysler Hemi Engines.
Dave's Early Hemi Page
Information, etc. (you could call it an Early Hemi Mecca)
Irish Jr's Site
Hemi Enthusiasm, an Early Hemi project car and a Hemi parts swap arena.
Chrysler Central's "Hemi Central"
General information and serial number details.
The Infamous Hemi
In-depth history and technical information on all Chrysler Hemi Engines.
Power Play Early Hemi Parts|
Route 1, Box 95
Lowgap, N.C. 27024
|Hotheads Research & Racing Early
P.O. Box 9132
Apache Junction, AZ. 85278-9132
Automotive Innovations Unlimited|
1014 W. Barkley Street
Orange, CA 92868
Tech Info: (714)-639-7625
Egge Machine Co.|
11707 Slauson Ave.
SantaFe Springs, CA 90670
Kanter Auto Products|
76 Monroe St.
Boonton, NJ 07005
Quality Engineered Components
1150 Ryan Court
West Lynn, OR 97068
A-833 4-speed tranny adapters, information and other parts for Early Hemis.
202 Ryan Way South
San Francisco, CA 94080
Sanderson sells headers for Early Hemis. Their headers are conveniently available online through Century Performance. More Info:
2601 W. 7th Street
Reno, NV 89503-3325
Phone: (775) 770-1057
P.O. Box 14232
San Luis Obispo, CA 93406
Adapters for Mopar and Ch#*y transmissions as well as front covers and finned valve covers.
Performance Automotive Warehouse
21001 Nordhoff St.
Chatsworth, CA 91311
Rod and main bearings as well as performance cams for the Early Hemi.
Chris Neilson Cams
Farmington, UT 84025
New cams for Early Hemis.
3299 Cherry Avenue
Long Beach, CA 90807
Early Hemi parts.
547 Sinclair Frontage Rd.
Milpitas, CA 95035
Transmission adapters, Early Hemi parts.
1320 Southeast Armour Road
Bend, OR 97702
Early Hemi pushrods.
2316 San Fernando Road
Los Angeles, CA 90065
Weiand manufactures performance intake parts, including a dual four barrel intake manifold as well as blower manifolds for Early Hemis.
Offenhauser Sales Corp.
5300 Alhambra Ave.
Los Angeles, CA 90032
Offenhauser makes intake manifolds for Early Hemis.
Van Buran, AR 72956
26555 Northwestern Hwy.
Southfield, MI 48034
Carbs, engine and miscellaneous parts for nearly all engines. Available through distributors.
7450 N. McCormick Blvd.
Skokie, IL 60076
Fel-Pro offers high quality gaskets which will fit the Early Hemi engine.
A very special thanks to Duffy Armitage for his assistance with this topic. If you would like extra advice or further information about Duffy's Early Hemi powered 1970 D-100, e-mail him at firstname.lastname@example.org.
Please Note: This page is intended as a guide for the project outlined, and is not guaranteed in any way. The information was supplied at the request of the author and is merely an extension of what was received. All the info is to the best knowledge of the author. Comments? Send in an Online Response.