Lot 7494: 1968 Plymouth Road Runner Hemi

To tell if a 1968 Plymouth Road Runner is a real factory Hemi, you need to check three main authentication points:

1. VIN Verification (Most Important)

• The 5th digit in the VIN must be “J” - this is the engine code for the 426 2x4bbl Hemi
• The VIN should start with “RM” (Plymouth Road Runner), followed by either:
  • 21 = 2-door sedan/coupe
  • 23 = 2-door hardtop
• Position 6 should be “8” for 1968 model year

For example, the VIN RM21J8A217494 on this vehicle breaks down as:

• R = Plymouth (B-body/Intermediate)
• M = Road Runner (Medium Price Class)
• 21 = 2-door coupe
• J = 426 Hemi engine ← This is your authentication key!
• 8 = 1968 model year
• A = Lynch Road, MI assembly plant

2. Fender Tag Codes The fender tag (located on the driver’s side inner fender) should show:

• Code 073 = “426-8bbl Hemi Engine”
• Code 094 = Hemi automatic transmission
• These codes confirm the car was ordered from the factory with the Hemi package

3. Engine Stampings A factory 426 Hemi block will have:

• Casting numbers: The block should have proper 426 Hemi casting marks
• Some engines may show “WT“ stamps - these indicate “Water Tested Replacement Block” (factory warranty replacement blocks)
• The engine should have VIN derivative stamps that match the last digits of the car’s VIN (when numbers-matching)

Important Notes for 1968:

• Only 726 Road Runner Hemis were built in 1968, making these incredibly rare
• Many clones exist with non-factory Hemi swaps
• Even if the original engine is no longer present (like the 1966 date code replacement block in this car), the VIN and fender tag confirm it was factory-built as a Hemi car

Want me to help you find other Hemi Road Runners for comparison? Check out our market page: https://classic.com/m/plymouth/road-runner/1st-gen/hemi/