All engines are stamped with an engine ID code, consisting of assembly plant code, production date and suffix code. V8 codes are stamped on a pad just forward of the right side (passenger) cylinder head. 6 cylinder engines are stamped on the passenger side of the block behind the distributor. The block casting number on small block and big block Chevy V-8 engine's are located on the ledge found at the rear of the block, most often on the driver's side. This ledge forms the mating surface between the block and the transmission bell housing. These particular codes designate the specific powerplant that was installed in the vehicle at the factory. Note, this is a general reference.

Code	Power plant	Equipment
AA	194-120 HP	Manual Transmission
AC	194-120 HP	Heavy Duty Clutch
AH	194-120 HP	Heavy Duty Clutch & A/C
AG	194-120 HP	Manual Transmission & A/C
AS	194-120 HP	Manual Transmission & Air Injection Reactor
AT	194-120 HP	Manual Transmission, A/C and Air Injection Reactor
AL	194-120 HP	Powerglide Automatic
AR	194-120 HP	Powerglide & A/C
AX	194-120 HP	Powerglide & Air Injection Reactor
AY	194-120 HP	Powerglide, A/C & Air Injection Reactor
CA	230-140 HP	Manual Transmission
CB	230-140 HP	Manual Transmission & A/C
BN	230-140 HP	Manual Transmission & Air Injection Reactor
BO	230-140 HP	Manual Transmission, A/C & Air Injection Reactor
CC	230-140 HP	Powerglide Automatic
CD	230-140 HP	Powerglide & A/C
BL	230-140 HP	Powerglide & Air Injection Reactor
B	230-140 HP	Powerglide, A/C & Air Injection Reactor
DA	283-195 HP	3-Speed Manual Transmission
DB	283-195 HP	4-Speed Manual Transmission
DI	283-195 HP	Manual Transmission & Air Injection Reactor
DK	283-195 HP	4-Speed Manual & Air Injection Reactor
DF	283-195 HP	Powerglide Automatic
DJ	283-195 HP	Powerglide & Air Injection Reactor
DG	283-220 HP	Manual Transmission
DL	283-220 HP	Manual Transmission & Air Injection Reactor
DM	283-220 HP	Powerglide & Air Injection Reactor
EA	327-275 HP	Manual Transmission
EB	327-275 HP	Manual Transmission & Air Injection Reactor
EE	327-275 HP	Powerglide Automatic
EC	327-275 HP	Powerglide & Air Injection Reactor
ED	396-325 HP	Manual Transmission
EH	396-325 HP	Manual Transmission & Air Injection Reactor
EK	396-325 HP	Powerglide Automatic
EM	396-325 HP	Powerglide & Air Injection Reactor
EF	396-350 HP	Manual Transmission
EJ	396-350 HP	Manual Transmission & Air Injection Reactor
EL	396-350 HP	Powerglide Automatic
EN	396-350 HP	Powerglide & Air Injection Reactor
EG	396-375 HP	Manual Transmission