1971 Corvette Engine Availability

ENGINE CODE:
The engine code is located on a pad on the block. It is at the base of and in front of the passenger side head.

CODE CID HP TRANS COMP BORE STROKE CARB
CJL 350 270 Manual 8.5:1 4.0 in 3 31/64 in 4 v Roch
CGT 350 270 Auto 8.5:1 4.0 in 3 31/64 in 4 v Roch
CGZ 350 330 Manual 9:1 4.0 in 3 31/64 in 4 v Holley
CJK 350 270 Auto 8.5:1 4.0 in 3 31/64 in 4 v Roch
CGY 350 330 HD Manual 9:1 4.0 in 3 31/64 in 4 v Holley
CPJ 454 365 Auto 8.5:1 4.25 in 4.0 in 4 v Roch
CPH 454 365 Manual 8.5:1 4.25 in 4.0 in 4 v Roch
CPW 454 425 Manual 9:1 4.25 in 4.0 in 4 v Holley
CPX 454 425 Auto 9:1 4.25 in 4.0 in 4 v Holley

ENGINE CASTING NUMBER:
The engine casting number is located to the left of the distributor on the top rear of the block.
"3970010" = 350 CID
"3963512" = 454 CID

ENGINE DATE CODE:
The engine date code is a two symbol code cast into the block. This code is located to the right of the distributor on the top rear of the block. A typical code would look like "B1" which decodes as February 1971. The second symbol denotes the year "0" = 1970 and "1" = 1971. The first symbol denotes the month by using the alphabet as shown below:

A JAN
B FEB
C MAR
D APR
E MAY
F JUN
G JUL
H AUG
I SEP
J OCT
K NOV
L DEC

HEAD CASTING NUMBER:
The engine casting number is located to the left of the distributor on the top rear of the block.
"3946074" = 454 CID LS6 425 hp
"3993820" = 454 CID LS5 365 hp
"3973487" = 350 CID 270 hp and 330 hp LT1