Spotters Guide - Mopar Muscle Magazine

It's been 50 years since Chrysler introduced American motorists to the wonders of the mass-produced hemispherical combustion chamber. What many people don't realize is that there were three distinct engine families of what's generically known as the "early Hemi," each with its own internal and external dimensions: the huge Chrysler Fire Power, the downsized DeSoto Fire Dome, and the even more compact Dodge Red Ram and Super Red Ram. Even though they share prominent design characteristics and look very similar, very few parts are interchangeable and they are all totally different than the '64-'71 426 Hemi. Here's an easy way to spot the difference: While the 426s have a front-mounted distributor, all the early Hemis have the sparker in the rear.

If you're looking for the biggest early Hemi power, stick with the Chryslers because speed parts, new and used, are plentiful. The "baby Hemis" from Dodge and especially DeSoto are more difficult because bolt-on aftermarket hop-up goodies are not as bountiful, but this lack of popularity makes baby Hemi core motors far less expensive. Though you can assemble any early Hemi from loose parts, smart money buys a complete long-block so all of the necessary parts are there for rebuilding. To help make sense of it all, we visited Reath Automotive and quizzed Bob Walker at Hot Heads Research.

The identification stamping for all early Hemis is located on the machined pad at the front of the block (arrow).

Chrysler Fire Power
Polished GMC blowers, square-wall M&H Racemaster slicks, nitro-methane, zoomie headers, finned M/T rocker covers, block-splitting fireballs, Halibrand mags, silver fi/resuits, and front motored dragsters are just a few of the things that come to mind when you think of the Chrysler Fire Power. Unleashed in 1951, this is the largest of the early Hemis, and thanks to decades of blown Fuel madness, even a mild single-carbed street runner drips with history and mystique. New and used parts availability is so strong that 90 percent of all early Hemi projects are Chrysler based.

 BoreStrokeCIMain Dia.Rod Dia.Rod LengthIn. Dia.Ex.Dia.Low Deck'51-'543.81253.6253312.{{{5000}}}2.2506.6251.811.50'553.81253.6253312.50002.2506.6251.941.75'56-'{{{57}}}3.93753.6253542.50002.2506.6251.941.75Tall Deck'57-'584.00003.9063922.68752.3756.9502.001.75

Chrysler Fire power Stamping Guide

• 331ci: C51-8, C52-8, C53-8, C541-8, C542-8, NE55, 3NE55, CE55, M45SP, R8, RS8, T8, V8, C5, C6, P3, P4, S7, W5, IND20, IND20A, IND24, IND24A, IND56, WG57, 3NE56
• 354ci: NE56, CE56, 3NE56, M45S-3, M45SP-3, K8-D9, T9, L8-D7, L8-D8, L8-D9, M8-D7, M8-D8, M8-D9C7, S7, IND56A, D501
• 392ci: NE57, 58N, CE57, 58C, 3NE57, 58N3

DeSoto Fire Dome
Following the Fire Power into battle by one year, the downsized DeSoto Fire Dome hit showrooms in '52. Though most racers went for the Chrysler's displacement advantage, Fire Domes were a favorite among builders of street-driven T-buckets, A-bones, highboys, and customs because they were plentiful, potent, and cheap. Stock rebuild parts are still available, but you'll need to hit eBay or the swaps for vintage multicarb intakes and other hop-up goodies. They're cheap to buy, expensive to build. When scrounging, note that the DeSoto Firesweep models used Dodge engines and drivetrains.

 BoreStrokeCIMain Dia.Rod Dia.Rod LengthIn. Dia.Ex. Dia.Low Deck'52-'543.6253.3442762.3752.0626.06251.841.50'553.{{{720}}}3.3442912.3752.0626.06251.841.50Tall Deck'56 Fire Dome3.7203.8003302.5002.2506.62501.941.75and Fireflite'56 Adventurer3.7813.8003412.5002.2506.62501.941.75'{{{57}}}3.7813.8003412.5002.2506.62501.941.75 '573.8003.8003452.5002.2506.62501.941.75

DeSoto Fire Dome Block Stamping Guide

• 276ci: S17, S16, S19, IND19A
• 291ci: S21, S22
• 330ci: S23, S24
• 341ci: S24A, S25, S26
• 345ci: S26A

Rocker Shaft Dimension
Sifting through a pile of rocker assembly parts at the swap meet marked "early Hemi"? Here's how to identify 'em. Note the substantial difference in size between the 392 Fire Power (top) and 270 Dodge Red Ram rocker assemblies shown here; no parts are interchangeable.

 DeSotoDodgeChryslerExhaust rocker stand height21 3/162 1/22 1/16Intake rocker stand height2 1/162 3/162 1/4Outermost head bolt spacing18 1/417 3/816 3/4Upper/lower head bolt distance3 1/23 7/164 5/16Rocker shaft diameter (I and E)7/87/87/8Rocker shaft length (I and E)19 5/1618 5/1617 3/16Rocker arm length (I)3 1/43 1/43 3/8Rocker arm length (E)4 5/84 3/163 7/8(All measurements in inches)

Where To Get What
Call the experts listed in our source box, and you'll find nearly anything you need, especially if it's a Chrysler you're working on. However, to ease your search, here are some highlights of companies that make stuff you might not have known about.
-David Freiburger

• General Doo-Dads: The primary sources for Hemi parts are Hot Heads Research, which covers all the brands of Hemis, and PAW, which has a special catalog just for Chryslers.
• Rebuilt Parts: While all the specialists have parts, the main sources for stock pistons, rings, and bearings are Egge Machine, Kanter Auto Parts-both of which carry Chrysler, Dodge, and DeSoto parts-and PAW for Chrysler engine kits.
• Cylinder Heads: Hot Heads makes new aluminum performance heads for Chryslers (based on the '55 354 design). For all-out vintage drag racing, you can get parts from Donovan Engineering and Mastodon.
• Distributors: Look to any of the Hemi specialists for adapters or conversion kits to use modern Chevy or small-block Mopar distributors in any Chrysler or Dodge (the low-deck Chrysler distributor is the same as the tall-deck Dodge). Mallory still makes distributors, and Vertex makes Dodge and Chrysler electronic distributors that look like real magnetos.
• Headers: Sanderson makes block-huggers for all the early Hemis, and Rodworks has them for Chryslers.
• Oil System: Many companies make adapters to use a small-block Mopar oil pump on a Chrysler, and Hot Heads has Dodge and DeSoto adapters in the works. You'll also find conversion adapters for spin-on oil filters. Milodon, Hot Heads, and G&H Enterprises all make oil pans.
• Water Pumps: Most sources have adapters to use a big-block Chevy pump on a Chrysler or a small-block pump on a Dodge, and sometimes the adapter is integral with the front cover (which is interchangeable with the Dodge and Chrysler). Rev Engineering claims to have been the first with this setup, and pulleys are also available.
• Balancers: Most often, a small-block Mopar balancer is machined to fit. BHJ has new units for Chryslers.
• Motor Mounts: Look to Hot Heads or Chassis Engineering for universal mounts to weld to your frame. All the early Hemis use the same ears on the block.
• Dress-Up: Many of the specialists have their own valve covers, front covers, and valley pans, or you can look to Moon (for Chryslers) and O'Brien Truckers (for all Hemis).
• Intakes: The sky's the limit for Chryslers. For Dodges, Offenhauser has the only new manifold we know of (PN 3D-3372), and it's a three-deuce. For DeSotos, search for ancient Weiand intakes on eBay or vintagespeed.com.
• Accessory Brackets: Need air conditioning or power steering on your Hemi? Our listed sources have all you need, especially Hot Heads and PAW.
• Trans Adapters: All the early Hemis use the same trans adapters, and you can mate virtually any GM or Mopar auto or manual with adapters from Capanna (Wilcap), Hyatt Engineering, or Quality Engineered Components. Offenhauser still has the stuff for older trannies.

Dodge Red Ram
Lagging behind Chrysler and DeSoto in the corporate hierarchy, Dodge had to wait until 1953 to introduce its Hemi offering, the Red Ram (called the Super Red Ram with the introduction of the 270 in 1955). From Bonneville to Muroc to Pomona, the Ram's small displacement combined with high specific output to make it a legend anywhere the rulebook classification called for 300 cubes or less. Always more popular than the DeSoto, vintage speed parts are more readily available, and today's aftermarket offers a surprising level of support.

Dodge Red Ram Block Stamping Guide

• 241ci: D44, D50, D51, D52, D53, IND18, IND18A
• 270ci: D553, M44S-3, VT342, VT344, VT346, J8, JS8, KA8, KS8, IND52
• 315ci: D500, K8-D4, K8-D5, K8-D6, L8-D4, L8-D5, L8-D6, W5, C5, P3, P4, M8-D6, IND53, IND54
• 325ci: KD500, IND56A1, D501

 BoreStrokeCIMain Dia.Rod Dia.Rod LengthIn. Dia.Ex. Dia.Low Deck'53-'543.4373.2502412.3751.93755.93751.751.41'553.6253.2502702.3751.93755.93751.751.41Tall Deck'563.6253.8003152.5002.25006.62001.871.53'{{{57}}}3.6873.8003252.5002.25006.62001.871.53