1955-59 GMC Indentification Guide
  

The purpose of this page is to help indentify the 1955-59 GMC pickup trucks. This information was taken from original GMC parts books.

GMC made fleet and commercial trucks that had different parts than the regular trucks and had a different appearance.

A note on 1959 GMC trucks, the parts books show bumper guards and the 1959 Magazine Ads and an 1959 GMC brochure do not have them.

  GMC Emblem 
XY Series T Series S Series
1955&1956  1957  1958&1959
Serial Number Example
101 8 PY 1001
Serial Number Breakdown
Model V8 Engine Series Production
101 8 Y 1001
*Note: 8 was used for V8 and nothing for six cylinder.
Place Of Manufacture
Oakland CA Pontiac MI St.Louis
C P S
Model Indentification
100 Series 150 Series 250 Series
1/2 Ton 3/4 Ton 1 Ton
TRUCK MODEL IDENTIFICATION

CHASSIS SERIAL NUMBER

Data Plate The chassis serial number is stamped on identification plate as illustrated. (Letter P in serial number indicates Pontiac, C indicates Oakland.)
6 Cyl ENGINE
SERIAL NUMBER
The engine serial number on 6 cylinder engine is stamped on a boss on crankcase just adjacent to the distributor (left illustration). The serial number on 8-cylinder engine is stamped on block on right side below manifold to front of drain cock (right illustration).
Always refer to serial numbers of chassis and engine, and model numbers of other units (transmission, etc.) when ordering parts.
8 Cyl
PARTS IDENTIFICATION PLATE

Data Plate
CAB AND BODY IDENTIFICATION
(Blank Plates are available-Part #2267999-Model 300 & up)
The "GMC Truck Service Parts Identification" plate mounted on inside of glove compartment door, provides identification of the major units of the vehicle. This identifying data also is shown in the parts listing. Therefore, reference to this plate before ordering parts, will insure correctness of the parts ordered. Cab and Cowl Models used on each chassis model can be determined by reference to following pages. Body models are shown in group 23.0005.

TRUCK MODEL IDENTIFICATION
Series
Letter
Model Wheelbase
(Inches)
Engine
Type
Front axle Rear axle TRANSMISSION Brakes Cab or Cowl
Std. Opt. Std. Opt. Std. Opt.
100 SERIES
Y
(1955)
Y
(1955)
X
(1956)
X
(1956)
T
(1957)
 
 
T
(1957)
 
S
(1958-9)
 
 
 
 
S
(1958-9)
 
 
101
102
101-8
102-8
101
102
101-8
102-8
101
102
 
 
101-8
102-8
 
101
102
 
 
 
 
101-8
102-8
 
 
114
123-1/4
114
123-1/4
114
123-1/4
114
123-1/4
114
123-1/4
 
 
114
123-1/4
 
114
123-1/4
 
 
 
 
114
123-1/4
 
 
248
(6 Cyl.)
288 & 316
(8 Cyl.)
270
(6 Cyl.)
316
(8 Cyl.)
270
(6 Cyl.)
 
 
347
(8 Cyl.)
 
270
(6 Cyl.)
 
 
 
 
336
(8 Cyl.)
 
 
GM F022
 
GM F022
 
GM F022
 
GM F022
 
GM F022
 
 
 
GM F022
 
 
GM F022
 
 
 
 
 
GM F022
-
 
-
 
Driving
 
Driving
 
Driving
 
 
 
Driving
 
 
Driving
 
 
 
 
 
Driving
GM SS (A)
H033 Hypoid
GM SS (A)
H033 Hypoid
GM SS (A)
H033 Hypoid
GM SS (A)
H033 Hypoid
Spicer 45 (A)
 
 
 
Spicer 45 (A)
 
 
Spicer 45 (A)
 
 
 
 
 
Spicer 45 (A)
-
 
-
 
Spicer 45 (A)
 
Spicer 45 (A)
 
-
 
 
 
-
 
 
-
 
 
 
 
 
-
GM 3 sp.
SM318
GM 3 sp.
SM318
GM 3 sp.
SM318
GM 3 sp.
SM318
GM 3 sp.
SM318
 
 
T85 3 sp. 
 
 
GM 3 sp.
SM318
 
 
 
 
GM 3 sp.
SM318
T89 3 sp., 4 sp., or
Hydra-Matic (4 sp.)
T89 3 sp., 4 sp., or
Hydra-Matic (4 sp.)
T89 3 sp., 4 sp., or
Hydra-Matic 177-CA
T89 3 sp., 4 sp., or
Hydra-Matic 177-CA
GM SM420 or
Hydra-Matic
177-CR
 
GM SM420 or
Hydra-Matic
177-CA
GM 4 sp.
SM420
Hydra-Matic
177-CA
Warner 3 sp.
T89B
GM 4 sp.
SM420
Hydra-Matic
177-CA
Vac
 
Vac
 
Vac
 
Vac
 
Vac
 
 
 
Vac
 
 
Vac
 
 
 
 
 
Vac
 
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
 
 
 
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
 
 
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
150 SERIES
Y
(1955)
Y
(1955)
X
(1956)
X
(1956)
T
(1957)
 
T
(1957)
 
S
(1958-9)
 
 
 
 
S
(1958-9)
 
 
152
 
152-8
 
152
 
152-8
 
152
 
 
152-8
 
 
152
 
 
 
 
 
152-8
 
 
 
123-1/4
 
123-1/4
 
123-1/4
 
123-1/4
 
123-1/4
 
 
123-1/4
 
 
123-1/4
 
 
 
 
 
123-1/4
 
 
248
(6 Cyl.)
288 & 316
(8 Cyl.)
270
(6 Cyl.)
316
(8 Cyl.)
270
(6 Cyl.)
 
347
(8 Cyl.)
 
270
(6 Cyl.)
 
 
 
 
336
(8 Cyl.)
 
 
GM F025
 
GM F025
 
GM F025
 
GM F025
 
GM F025
 
 
GM F025
 
 
GM F025
 
 
 
 
 
GM F025
-
 
-
 
Driving
 
Driving
 
Driving
 
 
Driving
 
 
Driving
 
 
 
 
 
Driving
GM SS (A)
H050 Hypoid
GM SS (A)
H050 Hypoid
GM SS (A)
H050 Hypoid
GM SS (A)
H050 Hypoid
Spicer 60 (A)
 
 
Spicer 60 (A)
 
 
Spicer 60 (A)
 
 
 
 
 
Spicer 60 (A)
-
 
-
 
-
 
-
 
-
 
 
-
 
 
-
 
 
 
 
 
-
GM 3 sp.
SM318
GM 3 sp.
SM318
GM 3 sp.
SM318
GM 3 sp.
SM318
GM 3 sp.
SM318
 
T85 3 sp. 
 
 
GM 3 sp.
SM318
 
 
 
 
GM 3 sp.
SM318
T89 3 sp., 4 sp., or
Hydra-Matic (4 sp.)
T89 3 sp., 4 sp., or
Hydra-Matic (4 sp.)
T89 3 sp., 4 sp., or
Hydra-Matic 210U
T89 3 sp., 4 sp., or
Hydra-Matic 210U
GM SM420 or
Hydra-Matic
210U
GM SM420 or
Hydra-Matic
300-GH
GM 4 sp.
SM420
Hydra-Matic
210U
Warner 3 sp.
T89B
GM 4 sp.
SM420
Hydra-Matic
300-GH
Vac
 
Vac
 
Vac
 
Vac
 
Vac
 
 
Vac
 
 
Vac
 
 
 
 
 
Vac
 
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
 
 
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
 
 
1754 Std. cab
1755 Deluxe cab
1777 Fl. back cowl
1780 Cowl W/W/S
  GMC Emblem 
  1955 GMC Index