the Assembly code is differant on the fisher body plate any one know why ? there is a H on the vin and FL1 on the fisher body plate

1965 - 1972 Buick VIN Decoding
Vechicle Identification Plates
1965-1971 Models
1st Digit - Division
4 = Buick
2nd and 3rd Digits - Series
33 = Special V6 (1965-67)
33 = Deluxe L6 (1968-69)
33 = Skylark L6 (1970-71)
34 = Special V8 (1965-67)
34 = Special Deluxe V8 (1968-69)
34 = GS350 (1968-70)
34 = GS (1971)
34 = Skylark V8 (1970-71)
34 = Sportwagon V8 (1970-71)
35 = Special Deluxe V6 (1965-67)
35 = Skylark V6 (1968-69)
35 = Skylark 350 (1970-71)
36 = Special Deluxe V8 (1965-67)
36 = Skylark V8 (1968-69)
41 = Sportwagon V6 (1965)
42 = Sportwagon V8 (1965)
43 = Skylark V6 (1965-67)
44 = Skylark V8 (1965-67)
44 = Skylark Custom (1968-71)
44 = Sportwagon V8 (1967-69)
46 = Skylark Gran Sport (1964-66)
46 = GS400 (1967-69)
46 = GS455 (1970)
48 = Sportwagon Custom V8 (1967-69)

1965-1971 models
4th and 5th Digits - Body Code
07 = 2 Door Post Coupe
17 = 2 Door Hardtop Coupe
27 = 2 Door Post Coupe
35 = 4 Door Station Wagon
36 = 4 Door Station Wagon
37 = 2 Door Hardtop Coupe
39 = 4 Door Hardtop Sedan
55 = 4 Door Sportwagon
56 = 4 Door Sportwagon Custom
65 = 4 Door Sportwagon
66 = 4 Door Sportwagon Custom
67 = 2 Door Convertible
69 = 4 Door Sedan

6th Digit - Model Year
5 = 1965
6 = 1966
7 = 1967
8 = 1968
9 = 1969
0 = 1970
1 = 1971

1965-1971 models
7th Digit - Assembly Plant Code
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
Last 6 Digits - Production Number

The 1968 Buick GS underwent a drastic structural change for 1968, losing 3 inches of wheelbase and 4.4 inches of overall length. Overall weight increase due in part to massive rear end styling and sail creases along the sides. The junior GS's power plant received an increase to 350 cubic inches but the 400 cubic inch unit stayed the same. A new model was introduced, the California GS. Sold exclusively in California, this model was basically a GS350 but with special "California" badges and trim, a standard two speed automatic transmission, a vinyl top, chrome exterior trim and wheels, and the Deluxe steering wheel. A very rare dealer installed option was also introduced in 1968 and it treated the 400 cid engine with a hotter cam, 11.0:1 compression, stronger valve springs and a reworked transmission. Officially pegged at a mere 345bhp, or just a 5 bhp increase over the base 400 cid engine, experts believe that it was more like 390bhp and it dropped 1/4 mile times by 1 second or more. It was called the "Stage 1 Special Package"( very rare for 1968) and was an indicator of great things to come.

Production for 1968:
GS350 2 Door thin pillar Coupe: 4,831

GS350 2 Door Hardtop: 8,317
GS400 2 Door Hardtop: 10,743

GS400 Convertible: 2,454

Engines:
GS350: 350 V8 280 bhp @ 4,600rpm, 375 lb-ft @ 2,800 rpm.

GS400: 400 V8 340 bhp @ 5,000rpm, 440 lb-ft @ 3,200 rpm.


Performance:
400/340: 0-60 in 5.8 sec, 1/4 mile in 14.2 sec @ 97 mph.