The Chrysler 354 Hemi (Gen 1) paired with a GM TH350 transmission is a quintessential “Hot Rod” setup. The 354, produced only in 1956, was the engine that powered the legendary Chrysler 300B, making it one of the first American production engines to achieve the “1 horsepower per cubic inch” milestone.

In 2026, this combination is prized for its vintage aesthetic (those massive valve covers) and the reliability of the GM automatic transmission.

1. Technical Profile: The “300B” Heart

The 354 is a “Gen 1” Hemi, characterized by its heavy cast-iron construction and a unique valvetrain that requires specific maintenance.

Listing Details

• 354ci Hemi V8
• .030″ Overbore
• Isky Racing Cams Camshaft
• Weiand High-Rise Intake Manifold
• Dual Edelbrock Performer Carburetors
• O’Brien Truckers Air-Cleaner Cover
• Chrome Proform Alternator
• Chevrolet-Style Short Water Pump
• Milodon High-Volume Oil Pump
• MSD Pro-Billet Distributor
• Sanderson Exhaust Headers
• Mooneyes Valve Covers
• Engine Stand
• TH350 Automatic Transmission
• Boss Hog Torque Converter

2. 2026 Market Valuation (Estimated USD)

Acquiring a 354 Hemi has become more expensive as they are increasingly used in period-correct “Gasser” and “Lead Sled” builds.

3. The “Marriage”: Adapting Hemi to TH350

Because Chrysler didn’t use the standard GM “Chevy” or “BOP” (Buick-Olds-Pontiac) bolt patterns in the 50s, a specialized adapter is required.

• The “Hot Rod” Standard: Brands like Hot Rod City or Wilcap are the go-to sources in 2026.

• Critical Note: You will need a specific flexplate and a starter relocation kit, as the original 1956 Chrysler starter position often interferes with modern frame rails or the TH350 case.

4. Critical “2026 Status” Maintenance

• The “Adjustable” Valves: Unlike modern Hemis, the 354 uses solid lifters. You must manually adjust the valve lash periodically. In 2026, many owners convert to hydraulic lifters during a rebuild to avoid this, though it slightly limits high-RPM potential.

• Oil Filter Conversion: Original 354s used a “bypass” oil filter system. For a 2026 build, a full-flow oil filter conversion is mandatory to prevent premature bearing wear.

• Lead Substitute: The original valve seats were not hardened for unleaded fuel. If the heads haven’t been rebuilt with hardened seats, you must use a lead substitute to prevent “valve seat recession.”

• Transmission Cooling: The TH350 is a workhorse, but a 700 lb Hemi generates significant heat. An external transmission cooler is highly recommended.

5. 2026 Expert Tip: Identify Your Block

The 354 was used in both Passenger Cars and Industrial/Truck applications.

• Passenger Car (Desired): Better heads and higher compression. Look for serial numbers starting with “NE56”.

• Industrial (Avoid for Performance): These often have lower compression and different water pumps. They are frequently used as “donor” blocks but require more work to make fast.