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Below is a listing of common identification numbers for the 1974 Corvette including engine block, head id, casting numbers and more.

Vehicle Identification Number
1Z37J4S400001 - 1Z37J4S440606
Digit Definition
1st 1 = GM Division = Chevrolet
2nd Z = Series = Corvette
3rd/4th Body Style:  37 = Coupe, 67 = Convert
5th Engine Type:  J = L48, T = L82, Z = LS4
6th 4 = Model Year = 1974
7th Assembly Plant:  S = St. Louis, MO.
Last 6 digits Production Number starting with 400001 and up.

1974 Corvette VIN Identification

Engine Suffix ID Numbers
CKZ: 350ci, 195hp, (manual transmission)
CLA: 350ci, 195hp, (automatic transmission)
CLB: 350ci, 195hp, (manual transmission, California emissions)
CLC: 350ci, 195hp, (automatic transmission, California emissions)
CLD: 350ci, 250hp, (automatic transmission)
CLH: 350ci, 250hp, (automatic transmission, California emissions)
CLR: 350ci, 250hp, (manual transmission)
CLS: 350ci, 250hp (California emissions, manual transmission)
CWM: 454ci, 270hp (manual transmission)
CWR: 454ci, 270hp (automatic transmission)
CWS: 454ci, 270hp, (automatic transmission, California emissions)
CWT: 454ci, 270hp, (California emissions, manual transmission)

Block ID Numbers
3970010: 350ci, 195hp, 250hp
3999289: 454ci, 270hp

Head ID Numbers
333882: 350ci, 195hp, 250hp
336781: 454ci, 270hp

Carburetor ID Numbers
Rochester Q-jet #7044221: 454ci, 270hp (manual transmission)
Rochester Q-jet #7044206: 350ci, 195hp (automatic transmission)
Rochester Q-jet #7044207: 350ci, 195hp (manual transmission)
Rochester Q-jet #70445210: 350ci, 250hp (automatic transmission)
Rochester Q-jet #7044211: 350ci, 250hp (manual transmission)
Rochester Q-jet #7044225: 454ci, 270hp (automatic transmission)
Rochester Q-jet #7044505: 454ci, 270hp (automatic transmission, California emissions)
Rochester Q-jet #7044506: 350ci, 250hp (automatic transmission, California emissions)
Rochester Q-jet #7044507: 350ci, 250hp (California emissions, manual transmission)

Cylinder Head Casting Number:
The cylinder head casting number is usually found on top of the cylinder head in between two valves and the rocker arm studs.

Cylinder Head Casting Date:
The cylinder head casting date is usually found adjacent to the cylinder head casting number. The casting date code is an alphanumeric sequenced number. The first digit is usually a letter which specifies the month that the block was cast. Some casting dates have been found with all digits being numbers, the first of which corresponds to the month.

Cylinder Head Casting Number Month Codes (1st Digit)
A - January E - May I - September
B - February F - June J - October
C - March G - July K - November
D - April H - August L - December

Example:  Flint Cylinder Head Casting Number - D 19 9

  • D:  Month = April
  • 19:  Casting Day = 19th
  • 9:  Casting Year = 1959

Example:  Tonawanda Cylinder Head Casting Number - D 19 59

  • D:  Month = April
  • 19:  Casting Day = 19th
  • 59:  Casting Year = 1959

Distributor ID Numbers
1112114: 454ci, 270hp
1112150: 350ci, 250hp
1112247: 350ci, 195hp
1112544: 350ci, 195hp (California emissions, manual transmission)
1112850: 350ci, 195hp (California emissions, manual transmission)
1112851: 350ci, 195hp (automatic transmission, California emissions)
1112853: 350ci, 250hp (automatic transmission)

Alternator ID Numbers
1100544: All engines with air conditioning.
1100950: All engines without air conditioning.