RPO for quick ratio steering box
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Joined: Oct 2002
Posts: 9,067
Likes: 1
From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
For Camaros, it was part of the Z28 and IROC package. I'm gonna assume for a Firebird it was std for a TA, GTA and Formula.
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Joined: Jul 1999
Posts: 1,466
Likes: 71
From: Alberta, Canada
Car: 1989 Camaro-1LE
Engine: TPI(s)
Transmission: 5 speed (MM5, MK6)
Axle/Gears: 3.45, 3.73
In a nut shell, if you got the upgraded suspension, you got the fast ratio steering box. It is part of the F41 or whatever code is for suspension.
On top of that, if you ordered the 16" tires, the steering box was substituded for the same fast ratio box, but with larger internal stops so the tires did not rub, as well the valving was different to accomodate the big tires.
So there was no RPO code to specify, it was part of the suspension on the car.
If you had a build sheet, it would certainly list an internal GM code for the box, which if I recall is the 2 letter code you find on the end of the boxes, for example YH. I don't recall the letter codes off the top of my head.
If you want a steering box, look for any 15" rim car with performance suspension. MAke sure the steering box is the Saginaw 800 series identified by the 4 bolts holding the cover on. This will be the fast ratio, 2.5 turns lock to lock box.
If you want the stiffer feeling, 2.25 lock to lock (wider turning radius) box, find a car with 16" wheels.
Mark.
On top of that, if you ordered the 16" tires, the steering box was substituded for the same fast ratio box, but with larger internal stops so the tires did not rub, as well the valving was different to accomodate the big tires.
So there was no RPO code to specify, it was part of the suspension on the car.
If you had a build sheet, it would certainly list an internal GM code for the box, which if I recall is the 2 letter code you find on the end of the boxes, for example YH. I don't recall the letter codes off the top of my head.
If you want a steering box, look for any 15" rim car with performance suspension. MAke sure the steering box is the Saginaw 800 series identified by the 4 bolts holding the cover on. This will be the fast ratio, 2.5 turns lock to lock box.
If you want the stiffer feeling, 2.25 lock to lock (wider turning radius) box, find a car with 16" wheels.
Mark.
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Joined: Sep 2002
Posts: 2,565
Likes: 10
From: Texas
Car: 1992 Formula Firebird
Engine: 305CID (LB9)
Transmission: World Class T5
Axle/Gears: 10-bolt, 4.10 gears
I know any WS6 car had the steering box. At least I am pretty sure on that one.
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Thanks for the info guys. I know my 92 RS, which came with the F41 suspension and 16 inch Z28 wheels has the quick ratio steering box, but I was just wondering if there was an actual rpo for it. I guess it was just part of the f41 in 92 I assume since I have no rpo for the box that I know of, but I do have the box.
i always thought that only irocs got the box, no matter what... its what made the iroc, the iroc. if anyone has an rpo code, id like to know.. i have a 87 Z28 and want to know if it came in my car... i have a high optioned car and want to know. thanks.
Supreme Member

Joined: Jul 1999
Posts: 1,466
Likes: 71
From: Alberta, Canada
Car: 1989 Camaro-1LE
Engine: TPI(s)
Transmission: 5 speed (MM5, MK6)
Axle/Gears: 3.45, 3.73
There is no RPO other than the suspension code. If you have a build sheet, you can read the 2 letter code which ultimately describes your steering box. TAke some cleaner, and wipe off the end plate on your steering box. Only use soap and water as the 2 letter code is painted on.
Just to clarify, you got the fast ratio box with any performance suspension. But you only got the 2.25 turn lock to lock box with 16" rims. It is not any faster ratio, still 12.5:1, but has larger stops for the big tires.
People will debate on which box is better. The 2.25 turn, does not turn as sharp, but has a stiffer feal. The 2.5 turn lock to lock actually turns sharper, but does not feel as stiff.
If your running BIG tires, then you want the 2.25 box. period.
Regarding IRocs. There was a factory 15" wheel option on the IROCs, or rather you could order the 16" wheels. So certainly there are some irocs around with the standard fast ratio box.
Mark.
Just to clarify, you got the fast ratio box with any performance suspension. But you only got the 2.25 turn lock to lock box with 16" rims. It is not any faster ratio, still 12.5:1, but has larger stops for the big tires.
People will debate on which box is better. The 2.25 turn, does not turn as sharp, but has a stiffer feal. The 2.5 turn lock to lock actually turns sharper, but does not feel as stiff.
If your running BIG tires, then you want the 2.25 box. period.
Regarding IRocs. There was a factory 15" wheel option on the IROCs, or rather you could order the 16" wheels. So certainly there are some irocs around with the standard fast ratio box.
Mark.
I bought an 89 IROC-Z (L98/700r4/2.77 9 Bolt) on Sunday. It has the FE2 suspension RPO and the 16" wheel RPO. Get this, it does not have an IROC RPO (this is kind of weird) but instead it has a Z28 RPO (not sure if that matters). The steering feels different compared to my other 3rd gens so I'm checking it out. I'm gonna find out what I have when I get some free time and see if it was changed by the previous owner. From what I've read I should have the quicker ratio box with larger stops from the factory. We'll see what happens I guess ... I'm hoping I just have a different box and not some sort of linkage problem ...
Last edited by CrazyHawaiian; Jan 19, 2004 at 06:42 AM.
Joined: Oct 2003
Posts: 508
Likes: 9
From: Columbus, Ohio
Car: 1986 Iroc
Engine: Afr 408
Transmission: T56 Magnum
Axle/Gears: Moser 9" 3.70s
I think that is because GM dropped the Z-28 name ( I forget which year, someone help me out, I want to say 89-90??) and replaced it with the Iroc-Z name. However, the RPO for IROC simply switched to the RPO for the Z-28. Also my Iroc has the quick ratio steering and it is an 86, and I like it. Not sure if that helps?
Supreme Member

Joined: Jul 1999
Posts: 1,466
Likes: 71
From: Alberta, Canada
Car: 1989 Camaro-1LE
Engine: TPI(s)
Transmission: 5 speed (MM5, MK6)
Axle/Gears: 3.45, 3.73
There were many steering boxes available in the thirdgen:
A great summary here:
http://www.chevelles.com/techref/shea_3.html
1982-83-84
WN
F Level IV
14:1
24-30
0.204 Dia
35 deg
WP
F Berlinetta
15-13
14-20
0.175 Dia
35deg 15min
WS
F Level III
12.7:1
24-30
0.204 Dia
35 deg
1985
WN
F Level II
14:1
24-30
0.204 Dia
35 deg
WP
F Berlinetta
15-13
14-20
0.175 Dia
35deg 15min
WS
F Level III
12.7:1
24-30
0.204 Dia
35 deg
XH
F Level IV
12.7:1
28-34
0.210 Dia
32 deg
1986
WS
F Z28 w/o FE2
12.7:1
24-30
0.204 Dia
35 deg
XH
F V8 w/FE2
12.7:1
28-34
0.210 Dia
32 deg
JL
F-Base
14:1
20-26
0.195 Dia
35 deg
1987 thru 93
WS
F Z28
12.7:1
24-30
0.204 Dia
35 deg
XH
F w/FE2 Level IV
12.7:1
28-34
0.210 Dia
32 deg
JL
F-Base
14:1
20-26
0.195 Dia
35 deg
A great summary here:
http://www.chevelles.com/techref/shea_3.html
1982-83-84
WN
F Level IV
14:1
24-30
0.204 Dia
35 deg
WP
F Berlinetta
15-13
14-20
0.175 Dia
35deg 15min
WS
F Level III
12.7:1
24-30
0.204 Dia
35 deg
1985
WN
F Level II
14:1
24-30
0.204 Dia
35 deg
WP
F Berlinetta
15-13
14-20
0.175 Dia
35deg 15min
WS
F Level III
12.7:1
24-30
0.204 Dia
35 deg
XH
F Level IV
12.7:1
28-34
0.210 Dia
32 deg
1986
WS
F Z28 w/o FE2
12.7:1
24-30
0.204 Dia
35 deg
XH
F V8 w/FE2
12.7:1
28-34
0.210 Dia
32 deg
JL
F-Base
14:1
20-26
0.195 Dia
35 deg
1987 thru 93
WS
F Z28
12.7:1
24-30
0.204 Dia
35 deg
XH
F w/FE2 Level IV
12.7:1
28-34
0.210 Dia
32 deg
JL
F-Base
14:1
20-26
0.195 Dia
35 deg
Originally posted by aaron7
If you got an Iroc with 15" wheels stock (me
) you do NOT have the quick ratio. It only came with 16" wheels.
If you got an Iroc with 15" wheels stock (me
) you do NOT have the quick ratio. It only came with 16" wheels. Joined: Nov 2005
Posts: 2,346
Likes: 1
From: Naples, FL
Car: 91 RS Camaro, 75 L82 Corvette
Engine: LO3, 383 Stroker
Transmission: 700R4, TH400
Axle/Gears: 4th gen 3.23 posi/LS1 discs, stock
Can someone explain this more.
I understand the year of course.
And the two letter codes that are inked stamped on the front of the steering box.
But whats the deal with the level II,III and IV?
I know FE2 is level two option group. Are those just option groups available in those years?
I also understand the ratio is either 14:1 or 12.7:1.
But the numbers below the ratio, whats that?
And the Number that is 0.XXX DIA, what is that?
I think I understand that the last line is the degree turning radius is either 32 or 35 degrees. I assume that the 15 inch wheel cars got the 35 degree and the 16 inch wheeled cars got the 32 degree (I dunno).
Basiclly, I have a 91 RS with the RS group 2 (which included 16 inch wheels), According to the restoration packate I got from GM, the RS's only got the 14:1 box. So I got a box with "WS" stamped on it at the junk yard for 25 bux. I guess I'll have to see if I can look and see the stamp on the front of my box. But I'm pretty sure the box I got is going to be better than the box on the car now.
I understand the year of course.
And the two letter codes that are inked stamped on the front of the steering box.
But whats the deal with the level II,III and IV?
I know FE2 is level two option group. Are those just option groups available in those years?
I also understand the ratio is either 14:1 or 12.7:1.
But the numbers below the ratio, whats that?
And the Number that is 0.XXX DIA, what is that?
I think I understand that the last line is the degree turning radius is either 32 or 35 degrees. I assume that the 15 inch wheel cars got the 35 degree and the 16 inch wheeled cars got the 32 degree (I dunno).
Basiclly, I have a 91 RS with the RS group 2 (which included 16 inch wheels), According to the restoration packate I got from GM, the RS's only got the 14:1 box. So I got a box with "WS" stamped on it at the junk yard for 25 bux. I guess I'll have to see if I can look and see the stamp on the front of my box. But I'm pretty sure the box I got is going to be better than the box on the car now.
Originally Posted by Mark_ZZ3
There were many steering boxes available in the thirdgen:
A great summary here:
Shea_3, Saginaw Power Steering Ratio Spread Sheets
1982-83-84
WN
F Level IV
14:1
24-30
0.204 Dia
35 deg
WP
F Berlinetta
15-13
14-20
0.175 Dia
35deg 15min
WS
F Level III
12.7:1
24-30
0.204 Dia
35 deg
1985
WN
F Level II
14:1
24-30
0.204 Dia
35 deg
WP
F Berlinetta
15-13
14-20
0.175 Dia
35deg 15min
WS
F Level III
12.7:1
24-30
0.204 Dia
35 deg
XH
F Level IV
12.7:1
28-34
0.210 Dia
32 deg
1986
WS
F Z28 w/o FE2
12.7:1
24-30
0.204 Dia
35 deg
XH
F V8 w/FE2
12.7:1
28-34
0.210 Dia
32 deg
JL
F-Base
14:1
20-26
0.195 Dia
35 deg
1987 thru 93
WS
F Z28
12.7:1
24-30
0.204 Dia
35 deg
XH
F w/FE2 Level IV
12.7:1
28-34
0.210 Dia
32 deg
JL
F-Base
14:1
20-26
0.195 Dia
35 deg
A great summary here:
Shea_3, Saginaw Power Steering Ratio Spread Sheets
1982-83-84
WN
F Level IV
14:1
24-30
0.204 Dia
35 deg
WP
F Berlinetta
15-13
14-20
0.175 Dia
35deg 15min
WS
F Level III
12.7:1
24-30
0.204 Dia
35 deg
1985
WN
F Level II
14:1
24-30
0.204 Dia
35 deg
WP
F Berlinetta
15-13
14-20
0.175 Dia
35deg 15min
WS
F Level III
12.7:1
24-30
0.204 Dia
35 deg
XH
F Level IV
12.7:1
28-34
0.210 Dia
32 deg
1986
WS
F Z28 w/o FE2
12.7:1
24-30
0.204 Dia
35 deg
XH
F V8 w/FE2
12.7:1
28-34
0.210 Dia
32 deg
JL
F-Base
14:1
20-26
0.195 Dia
35 deg
1987 thru 93
WS
F Z28
12.7:1
24-30
0.204 Dia
35 deg
XH
F w/FE2 Level IV
12.7:1
28-34
0.210 Dia
32 deg
JL
F-Base
14:1
20-26
0.195 Dia
35 deg
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