Engine Identification
cont.
Engine VIN numbers and locations
The VIN number is what defines a "numbers matching" engine, and is the most important thing stamped on the block, in relation to verification of a "numbers matching" combination.
67-70 400/430/455
'71 455
Early '71 block
Later "861" Block
These pictures show the variation in VIN number placement on a 1971 block. They changed the location slightly, the early 71 engines were built with the 70 style "738" block, the later engines went to the "861" casting number block, and the location changed slightly. Look carefully, and you will see that the block casting is slightly different in this area.
72-76 455
The "861" block was carried over till mid year '72, and you often will find a 72 VIN in the late '71 location. I have seen them here, and also in the locations shown below, which was common for most '72's and all 73-76 engines. Generally speaking, if you have an early 72 engine with an "861" casting number, you will find the VIN as shown above. Mid Year '72 they changed to the "735" casting number, which remained thru a few different mold revisions, till the end of the production run in 1976. All "735" casting number blocks that I have seen, have the VIN number in the location pictured below.
On the passenger side, above the oil pressure sender, next to the timing cover. Stamped vertically
VIN number deciphering
In the '71 block pictured above, we see this number:
41H157128
4= Buick Motor Division
1= 1971- Year of the engine (0-6 for the 455's)
H= Final assembly plant for the vehicle it was originally installed in.
-
B = Baltimore, MD
C = South Gate, CA
D = Atlanta, GA
G = Framingham, MA
H = Flint, MI
I = Oshawa, Ontario (Canada)
K = Kansas City, MO
V = Bloomfield, IL
X = Kansas City, KS
Y = Wilmington, DE
Z = Fremont, CA
157128 - Last six digits of the vehicle's VIN
This is a sequential number unique to a particular vehicle
Performance tip
Due to a casting revision for the 1975 model year, the 455 block was treated to more material in the deck and cylinder wall areas. These blocks all carry the "735" casting number, and feature one other distinct characteristic. "455" was cast into the block, just above the starter, as pictured below.
