Suburban 1/2 Ton 2WD V8-454 7.4L (1987)
Muffler: All Technical Service Bulletins
Exaust - Noisy or Low Hanging Mufflers
Number:
88-393-6F
Section:
6F
Date:
FEB., 1989
Subject:
NOISY OR LOW HANGING MUFFLERS
Model and Year:
1987-88 R/V MODELS WITH 5.7L OR 7.4L
(VIN CODE K OR N) ENGINE
TO:
ALL CHEVROLET DEALERS
Customer comments may be received on 1987 and 1988 R/V models built prior to VIN breakpoint (JF165082) equipped with 5.7L or 7.4L engine, of
low hanging or throaty sounding (rumbling on acceleration) mufflers. Mufflers designed for usage on TBI equipped engines are of a high flow/low
restriction design for increased engine performance and are somewhat louder than mufflers used in previous years. If either of these conditions are
experienced, they can be repaired by installing a revised muffler and tailpipe assembly.
Parts Information
Parts
Quantity
Number
Description
Application
Required
15616421
Muffler
R1,2 5.7L Federal
1
(NA5/NA6)
R2
7.4L Export (NM8)
15616422
T/Pipe
R1,2 5.7L Federal
1
(NA5/NA6)
R2
7.4L Export
(NM8)
15616423
Muffler
R2
5.7L Calif.
(NB2)
1
R2
7.4L Federal
(NA5/NA6)
15616424
T/Pipe
R2
5.7L Calif.
(NB2)
1
R2
7.4L Federal
(NA5/NA6)
15616425
Muffler
V1,2 5.7L Federal
1
(NA5/NA6)
Parts
Quantity
Number
Description
Application
Required
15616426
T/Pipe
V1,2 5.7L Federal
1
(NA5/NA6)
379360
Clamp
R/V 1, 2 5.7L only
2
15624612
Hanger Muffler
V1,2 only
1
15624613
Shield Muffler
All
1
14029140
Bracket, Shield
All
2
15549331
Hanger T/Pipe
R1,
2
1
15549332
Hanger T/Pipe
V1,
2
1
