Spring Codes

[Ccmano]

This should be a sticky.... courtesy of Hib Halverson, found this researching for a friend. Thank you Hib!

It seems I have an FHA on my 90’.

H


C4 Spring Code Chart

compiled by Hib Halverson
©2007 Shark Communications

Preface Notes:

1) GM had two RPO subsystems during the C4 era. There were engineering RPOs and marketing RPOs. What consumers knew as Z51 or Z07 was actually a combination of the FE3 (96) or FE7 (84-95) HD suspensions with other performance-related options. Some GM parts data refers to FE3 or FE7. When those RPOs are listed, it refers to cars optioned with either Z51 (84-91, 96) or Z07 (92-95).

2) In MY89-91, Selective Ride Control (SRC), which many refer to by its RPO, FX3, could be ordered in combination with Z51, however, a little-recognized production change which always occured in those MYs when those two RPOs were ordered together was a downgrade to base level (FE1) springs, front lower control arms and stabilizer bars. In those MYs the only conditions under which FE7 was present were; 1) if the car was ordered with Z51 and without FX3 or 2) it was an 90 or 91 Corvette Challenge car.

3) For MY92-95, FX3 and FE7 was added. A new RPO, Z07, was released for this combination. For MY92-95, FX3 was, also, available as a stand-alone option.

Coupe, front*

HMZ 84 w. Z51
BMB 84 base, 85-87 with w. Z51
HKX, HMP 85-87 base
FHA 88-91 base, 89-91 w. FX3&Z51, ZR1*
FHB 88-91 w. Z51
AA 90-91 w. ZR1*
FSS 92-95 base, 92-93 w. FX3
FSK 92-95 w. Z07
FSM 92-95 w. ZR1*
HA 94-95 w. FX3
22173028 96 base
17999032 96 w. Z51
Per Mark Haibeck all ZR1’s he has seen came with FHA.

Convertible, front

HMN 86-87
FHC 88-91 base, 89-91 w. FX3
FSR 92-95 base
JA 94-95 w. FX3
22173029 95 w. FX3
17999031 96

Coupe, rear

BMF 84 base
BMH 84 w. Z51
NYR 85 base(?) 86-93 base, 89-90 w. FX3&Z51, 90-91 w. ZR1
NYU 85-91 w. Z51, 92-95 w. Z07
RHY 92-95 w. ZR1, 96 w. Z51
RHZ 94-96 base

Convertible, rear

RCA 86-96
22112254 94-95 w. FX3