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.

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-'543.81253.6253312.50002.2506.6251.811.50
'553.81253.6253312.50002.2506.6251.941.75
'56-'573.93753.6253542.50002.2506.6251.941.75
Tall 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