Power steering gear box

[7T2FISH]

Hello group. It's been a while had a stroke. I have a question about how to read the part number on the PS unit. Just what am I looking at? I have lost my white book. I have a late 71, early 72 Cuda. Special Ordered October 71 deliverd March 72 with bits of both years. The PS is the same as the PS in the AAR it is a Track Pack optioned car. I have no idea about the second or even third PS units I have stored. I need to know what numbers I am looking at versus opening them up and measuring washers.

 

[Challenger RTA]

This is a T/A box. It also had longer pitman and idler arm.

 

[Challenger RTA]

All 1971 340 e-body cars came standard with the S74 quick ratio steering box as of February 1, 1971.
Not really sure if was available as a separate option for 1971.
If your car was built after the above date, it should already have the fast ratio box installed unless it was changed out in the past. this was true for both 1971 Challengers and Cudas

Another thing to remember; most of the difference in quicker steering was due to the longer steering arm and special idler arm. The difference in the box itself was where the "stops' were set when going to extreme left and right turns. The stops were set shorter because the bigger 15 in tires would rub the fenders at extreme turns so the stops were set a little tighter to prevent this from happening.
The power steering pumps are different and cannot be interchanged because a higher pressure ps pump was installed (as per the bulletins)

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[Challenger RTA]

Read about the differences in 1970-1972 and the 1973 and later power steering sectors HERE. You did not say if it was a power steering gearbox but, basically, the 1973 and later power steering used the large-sector box while the 1970-1972 used the small-sector box.
The manual steering boxes used the small-sector pitman arm for all E-Body model years 1970-1974.
It sounds like you have a small-sector box.
There are small-sector pitman arms on Amazon. The MOOG K7102 is the small-sector pitman arm and is getting harder to find.

Check the casting number on the sector. These are the early E-Body (in bold) casting numbers which are small-sector boxes.
1970 Parts Catalog:
2537397 = 1970 A, B & E-bodies (non-T/A box)
2948900 = 1970 E-bodies w/quick ratio T/A box

1970-'71 Parts Catalog:
2948991 = 1971 A, B & E-bodies (non-T/A box)
2948900 = 1971 E-bodies w/quick ratio T/A box

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[340challconvert]

Rick Ehrenburg currently has the Moog small sector ebody pitman arm on his ebay site for $70.79
Amazon vendor has one for $108 and another vendor on ebay has one for $111.99
I picked up an extra from Rick today

 

[7T2FISH]

Thank you! This is valuable information. I have the 1.25in sector on both and they are both fast ratio with high pressure 1.06 pumps. So I can swap them out and it be a permanent swap. I'll send the orginal out for new seals. Again thank you all!