Quick Ratio vs Standard Pitman and Idler Arms

-
340-S Chicago

340-S Chicago

Member
Joined
Nov 28, 2019
Messages
11
Reaction score
5
Location
Chicago, IL
I'm in the middle of shoe-horning a 392 hemi into my 69 Barracuda and the new TTI headers look great, but my idler arm comes within 1/8" of the headers during travel.

I have manual, "quick ratio", steering with a 16:1 box. I recently replaced the steering box with one from P-S-T.com to tighten up the steering. It has a 1 1/8" sector shaft.

I have been told the non-quick ratio idler and pitman arms are shorter than quick ratio, but ordered them and they matched my current set (which I thought were quick ratio).

The part numbers I tried were:
- Pitman Arm - Dorman PA7074PR
- Idler Arm - Moog K7042

Does anyone know if these are the quick-ratio arms?
- Are there different sizes, or is it just in the steering box?

Does anyone happen to have a part number for the shorter arms?

I appreciate any help!
 
Last edited:
The best thing to do IMO is switch to the 73-76 centerlink/pitman/idler and run a 16:1 manual steering box. Much more room on the later setup
 
you are correct, the fast ratio arms are longer than stock (by 1 1/2" iirc) and they only work with the 73~76 centerlink. the fast ratio stuff doesn't play nice with most headers-- or at least anything off the shelf that i know of.

if you're having clearance issues with the stock arms, a 73~76 setup clears up a bit more room, as JD noted as above.
 
I think you'll find 1/8 to be adequate, if not, you can elongate the bottom idler pivot bolt hole slightly to gain a little clearance. Then weld an appropriate flat washer to the bottom bracket to secure the hole/washer in place. Hope that makes sense .
Assuming you trimmed idler ball stud and castle nut as best possible.
 
Last edited:
junkyardhero said:
you are correct, the fast ratio arms are longer than stock (by 1 1/2" iirc) and they only work with the 73~76 centerlink. the fast ratio stuff doesn't play nice with most headers-- or at least anything off the shelf that i know of.

if you're having clearance issues with the stock arms, a 73~76 setup clears up a bit more room, as JD noted as above.
Click to expand...
Borg 38.JPG


Yeah, there is a noticeable difference in the length.
 
The "Quick Ratio " arms were intended to go on a standard ratio box. Also they were initially intended to be used on "E/B" body cars. Im sure that is why there is some clearance issues with "A" body cars. If you install one of the quick pitman arms on a 16-1 box the actual ratio at the wheels is closer to 12-1.
 
mod5v said:
The "Quick Ratio " arms were intended to go on a standard ratio box. Also they were initially intended to be used on "E/B" body cars. Im sure that is why there is some clearance issues with "A" body cars. If you install one of the quick pitman arms on a 16-1 box the actual ratio at the wheels is closer to 12-1.
Click to expand...
I had that combo for a while. It wasnt bad.
 
mod5v said:
The "Quick Ratio " arms were intended to go on a standard ratio box. Also they were initially intended to be used on "E/B" body cars. Im sure that is why there is some clearance issues with "A" body cars. If you install one of the quick pitman arms on a 16-1 box the actual ratio at the wheels is closer to 12-1.
Click to expand...
This explains my original confusion. Thank you!

I think I'll try to find a way to sqeek out a few more millimeters and run it. It's nice to know there may be an option with the later center-link and arms if it hits.
 
4mulas said:
Wow, it’s good to see these side by each!

To the OP - I believe TTI references that some of their products are NOT intended for use with longer quick ratio arms. Read your tti instructions too for help
Click to expand...
The TTI instructions (and follow up call) was the original source of my confusion. Between that and a couple other conversations, I was convinced my '69 came with longer arms as well as the 16:1 box for the factory quick ratio option. It seems '69 only had one length of arm and the factory quick ratio option was limited to the 16:1 steering box.

THANK YOU ALL FOR THE HELP!!!
 
340-S Chicago said:
The TTI instructions (and follow up call) was the original source of my confusion. Between that and a couple other conversations, I was convinced my '69 came with longer arms as well as the 16:1 box for the factory quick ratio option. It seems '69 only had one length of arm and the factory quick ratio option was limited to the 16:1 steering box.

THANK YOU ALL FOR THE HELP!!!
Click to expand...
I’m pretty sure Quick ratio arms are aftermarket not factory. Yes the factory, if offered, would have a different worm and sector in the steering box to make a quick ratio option.

If you added a longer arm to a already quick ratio box I can imagine what the final effective ratio would be and also how very hard and stiff the steering would be…
 
Factory manual steering boxes were either 24:1 or 16:1, the fast ratio boxes were 16:1 and were offered only on A-bodies from ~1965 to 1969. The fast ratio manual steering boxes had standard length idler and pitman arms, the ratio was from the worm gear inside the box.

The only cars that got factory fast ratio pitman arms were the TA/AAR E-bodies, and that was a 16:1 power steering box with a fast ratio pitman for a final ratio of ~12:1. But again, that was a power steering set up.
 
4mulas said:
I’m pretty sure Quick ratio arms are aftermarket not factory. Yes the factory, if offered, would have a different worm and sector in the steering box to make a quick ratio option.

If you added a longer arm to a already quick ratio box I can imagine what the final effective ratio would be and also how very hard and stiff the steering would be…
Click to expand...
they weren't factory for our cars, but for E-bodies they were.

yeah, 16:1 manual box with the QR arms on the street is not anybody's idea of a good time.
 
You must log in or register to reply here.
-

Back
Top