Model Identification

Truck models, listed in tables, are identified using manufacturers letter and number designations. The letters identify the vehicle model series (i.e., "C" is conventional chassis, including Pickup, Blazer and Suburban). The number reference identifies the vehicles load capacity. Refer to following charts for actual letter and number designations.

Vehicle Series	I.D. Letter
Conventional Chassis (2-WD)	C
Conventional Chassis (4-WD)	K
Conventional Van Chassis	G
Forward Control/Stepvan Chassis	P

Chevrolet Number	GMC Number	Ton Capacity
10	1500	1/2
20	2500	3/4
30	3500	1

Vehicle Model, Series & Engine		Application	Transmission	Equipment Note	Figure Number
LIGHT DUTY
4.1L (250") 6-Cyl.
	C10/20	Fed.	Man.		1
		Fed.	Man.	Aux. Tk.	2
		Fed.	Auto.		(1)
		Fed.	Auto.	Aux. Tk.	3
		Fed. & Calif.	Man.	A.I.R.	4
		Fed. & Calif.	Man.	Aux. Tk. & A.I.R.	5
		Fed. & Calif.	Auto.	A.I.R.	6
		Fed. & Calif.	Auto.	Aux. Tk. & A.I.R.	7
		Fed.	Man.		8
		Fed.	Man.		9
		Calif.	Auto.		(1)
		Fed.	Man.	Aux. Tk.	10
	K10/20	Fed.	Auto.		(1)
		Fed.	Auto.	Aux. Tk.	3
		Fed.	Man.		1
	G10/20	Fed.	Man.		1
		Fed.	Auto.		11
MEDIUM DUTY
	4.1L (250") 6-Cyl. C10 & K10	Calif.	Man.	A.I.R.	4
HEAVY DUTY
	4.8L (292") 6-Cyl. C20/30 & K20/30	Fed. & Calif.	Man. & Auto.	A.I.R.	12
		Fed & Calif.	Man. & Auto.	A.I.R.	13
	P20/30	Fed. & Calif.	Man. & Auto.	A.I.R.	12
LIGHT DUTY
5.0L (305") V8
	C10/20 & K10/20	Fed.	Man.		14
		Fed.	Auto.		(1)
		Fed.	Man.		15
		Fed.	Auto.		16
		Fed.	Man.	A.I.R.	17
		Fed. & Calif.	Auto.	A.I.R.	18
		Calif.	Auto.	A.I.R.	19
	G10/20	Fed.	Man.		14
		Fed. & Calif.	Auto.	A.I.R.	18
		Fed. & Calif.	Auto.	A.I.R.	19
MEDIUM DUTY
	5.0L (305") V8 C20	Calif.	Auto.	A.I.R.	19
LIGHT DUTY
5.71 (350") V8
	C10/20 & K10/20	Calif.	Auto.		(1)
		Fed.	Man.		(1)
		Fed.	Auto.	A.I.R.	20
		Fed.	Auto.	A.I.R.	18
	G10/20	Fed.	Man.	A.I.R.	21
		Fed.	Auto.	A.I.R.	22
		Fed. & Calif.	Auto.	A.I.R.	19
	5.71 (350") Diesel V8	Fed. & Calif.	Auto.		(1)
MEDIUM DUTY
5.71 (350") V8
	C10/20	Calif.	Auto.	A.I.R.	18
	G10/20	Calif.	Auto.	A.I.R.	19
HEAVY DUTY
5.71 (350") V8
	C20/30 & K20/30	Fed.	Man. & Auto.	A.I.R.	23
		Fed.	Man. & Auto.	A.I.R.	24
		Fed. & Calif.	Man. & Auto.	A.I.R.	25
	G30 & P20/30	Fed.	Man. & Auto.	A.I.R.	24
		Fed. & Calif.	Man. & Auto.	A.I.R.	25
		Fed.	Man.	A.I.R.	26
HEAVY DUTY
7.4L (454") V8
	C20/30 & K20/30	Fed. & Calif.	Man. & Auto.	A.I.R.	27
		Fed. & Calif.	Man. & Auto.	A.I.R.	28
(1) Diagrams not available from General Motors.

EMISSION CONTROL DEVICE ABBREVIATIONS 

AIR  - Air Injection Reactor

DVTR  - Diverter Valve

EFE  - Early Fuel Evaporation

EGR  - Exhaust Gas Recirculation

PCV  - Positive Crankcase Ventilation

TRC  - Throttle Return Control

TVS  - Thermal Vacuum Switch