Hitman's Pontiac Trans Am Page     |   1978 Pontiac Trans Am
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Pontiac Historical Services
 
The package that you receive from Pontiac Historical Services lists all of the specifications for any 1978 Firebird, Esprit, Formula, and Trans Am.  I don't have all of them listed here, but at least this will give you an idea of what is included.  I tried to list on this page the most general information, but it does have much more detail than what is listed here.
Car Body and Dimensions, Power Combinations, Engine General, Engine Exhaust, Engine Fuel, Engine Cooling, Carburetor, Electrical System
Transmission, Tires and Wheels, Brakes, Suspension, Lamps, Weights
(Click on the Link to be taken directly to that Section)
Car and Body Dimensions 
(These measurements are in inches unless otherwise noted)
Firebird
2FS87
Firebird Esprit
2FT87
Firebird Formula
2FU87
Firebird Trans Am
2FW87
Width
Tread Front
61.3
61.6
Tread Rear
60.0
60.3
Vehicle Width
73.4
Vehicle Width w/Front door open
140.5
Length
Wheelbase
108.2
Vehicle Length
196.8
Overhang Front
42.8
Overhang Rear
45.9
Upper Structure Length
94.2
Rear Wheel C/L "X" Coordinate
86.7
Cowl Point "X" coordinate
9.4
Height
Vehicle Height
49.3
49.3
49.5
49.5
Cowl point to ground
35.7
35.9
Deck point to ground
35.6
35.8
Windshield Slope Angle
57.4 deg.
Ground Clearance
Front bumper to ground
11.7
11.6
Rear bumper to ground
10.2
10.5
Angle of Approach
18.4 deg.
18.5 deg.
Angle of Departure
10.4 deg.
10.7 deg.
Rear axle Differential to ground
6.8
Min. Running ground clearance
5.2
5.3
Location of Min. ground clearance
Catalytic Converter
Power Combinations 
( F= Federal          A = Altitude          C = California )
(Federal/High Altitude Engine/Axle Combinations available all states except California.)
(High Altitude Engine/Axle Combinations not recommended for Low Altitude.)
Series Availability
Code
cu. in.
Carb.
Comp.
Ratio
(x to 1)
BHP
@ RPM
Torque @ RPM
Exhaust S=Single
D=Dual
Transmission
Axle Ratio
Standard:
Firebird and Esprit
LD5
231
2
8
105
@3400
185
@2000
S
3-Speed
Manual,
Automatic
3.08 F
2.56, 3.23 F
2.56 C
Optional:
Firebird and Esprit
LG3
305
2
8.4
145
@3800
245
@2400
S
4-Speed
Manual,
Automatic
3.08 F
2.41 F

California
LG3
305
2
8.4
135
@3800
240
@2000
S
Automatic
2.41 C
LM1
350
4
8.2
170
@3800
270
@2400
4-Speed
Manual,
Automatic
3.08 F
2.41, 3.08 F
California & Altitude
LM1
350
4
8.2
160
@3800
260
@2400
S
Automatic
3.08 A
2.41, 3.08 C
Series Availability
Code
cu. in.
Carb.
Comp.
Ratio
(x to 1)
BHP
@ RPM
Torque @ RPM
Exhaust S=Single
D=Dual
Transmission
Axle Ratio
Standard:
Formula
LG3
305
2
8.4
145
@3800
245
@2400
S
4-Speed
Manual,
Automatic
3.08 F
2.41 F, C
Optional:
Formula
LM1
350
4
8.2
170
@3800
270
@2400
S
4-Speed
Manual,
Automatic
3.08 F
2.41, 3.08 F
California & Altitude
LM1
350
4
8.2
160
@3800
260
@2400
S
Automatic
3.08 A
2.41, 3.08 C
Formula
W72
400
4
8.1
220
@4000
320
@2800
D
4-Speed
Manual,
Automatic
3.42 F
3.23 F
L78
400
4
7.7
180
@3600
325
@1600
S
Automatic
2.56 F
L80
403
4
7.9
185
@3600
320
@2000
S
Automatic
2.56, 3.08 A
2.56, 3.23 C
Series Availability
Code
cu. in.
Carb.
Comp.
Ratio
(x to 1)
BHP
@ RPM
Torque @ RPM
Exhaust S=Single
D=Dual
Transmission
Axle Ratio
Standard:
Trans Am
L78
400
4
7.7
180
@3600
325
@1600
S
Automatic
2.56 F
W72
400
4
8.1
220
@4000
320
@2800
D
4-Speed
Manual,
Automatic
3.42 F
3.23 F
Optional:
Trans Am
L80
403
4
7.9
185
@3600
320
@2000
S
Automatic
2.56, 3.08 A
2.56, 3.23 C

Engine General: 
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LD5/231
LG3/305
LM1/350
L78/400
W72/400
L80/403
Type
V6 90° OHV
V8 90° OHV
Engine Weight (lbs.)
204.0 MT
191.7 AT
246.9 MT
235.8 AT
271.7 MT
260.0 AT
298.2 MT
286.9 AT
296.0 AT
Firing Order
1-6-5-4-3-2
1-8-4-3-6-5-7-2
1-8-4-3-6-5-7-2
Recommended Fuel
Unleaded 91 Octane (or higher)
Normal Oil Pressure (lb@rpm)
37 @ 2400
32-40 @ 2000
35-40@2600
55-60@2600
30-45@1500
Capacity of Crankcase
4
5
4
Fuel Tank
21 US gal.
Idle Speed AT
MT
(* - with AC on)
800 rpm
600 rpm
700 rpm
500 rpm*
600 rpm
500 rpm*
N/A
500 rpm*
775 rpm
600 rpm*
N/A
550 rpm*
Carburetor Make
Model

No. used
Rochester
2GE
2GC
M4MC
2 bbl.
4 bbl.
Cooling System Capacity
15.8 gal.
17.5 gal.
18.4 gal.
20.4 gal.
Timing Manual
15° @
800 RPM
4° @
600 RPM
6° @
700 RPM
N/A
18° @
775 RPM
N/A
Timing Automatic
15° @
600 RPM
4° @
500 RPM
8° @
500 RPM
16° @
675 RPM
18° @
775 RPM
20° @
1100 RPM
Spark Plugs
Gap
R46TSX
R45TSX
R45TSX
R46SZ
.060 in.
.060 in.
.060 in.
.080 in.

Tires and Wheels: 

Firebird
Esprit
Formula
Trans Am
Special Performance Trans Am
Size, Load Range, Ply
FR 78 x 15B
GR 70 x 15B
P225/70R15
Type
Steel Belted Radials
Recom. Inflation  Fr.
Rear
28 psi.

30 psi.
30 psi.

30 psi.
Rims
15x6JJ
15x7JJ
15x8JJ

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