Quote:
: Hey Group,
: Does anyone have any experience with the
: tighter turning radious manual steering
: boxes on the (after)market ?
: I believe the stock unit on my 64 Dart is 24:1
: (5 1/2 turns to lock), and I am thinking of
: shortening it to 20:1 (4 1/2 turns to lock).
: Gina
Mopar offered 3 ratios with the manual steering boxes:
the 24 to 1 ( really about 5.9 turns "lock-to-lock")
the 20 to 1 @ 4.9 LtoL
and the 16 to 1 @ 3.6 LtoL.
Actually the 3.6 came before the the 4.9, this was the "fast ratio" box for the 60's muscle cars and was quite a hard box to steer, especially in a B-Body with a big block and wide "polyglass" belted tires. (My Dad's 69 Road Runner had this, along with the 4-speed, Mom made him sell the car because she "could not drive it". (but the teenage kids could! =:-O
I think that 3.6 box gave the fast ratio steering option a bad rap because you just do not see many of these fast ratio boxes around, not in the junkyards, not at the swap meets and up untill recently, not offered by the "aftermarket suppliers". I speak from first hand (over hand, over hand,...) knowledge, I have "spun" every Mopar steering box I have come across, 25 years worth, and have only found 3 fast ratios out of hundreds checked. (2 of the 3.6s and one 4.9)
If you really must have a fast ratio, Firm Feel now offers them so just save your $$$ and buy a new one. For the street, I would get the 4.9 turn unit. ( I have to say that I really like the 3.6 I have in my Dragcar. Some people say "what a waste" but the car is light, has skinny front tires, is a breeze to get positioned into the water box or get over to the correct lane and when the "tail wags", it's easer to keep the car out of the wall)
Just for reference, the power steering box has a 15.7 to 1 ratio (about 3.5 turns LtoL) so if you want to get an idea on how a 3.6 box acts, just drive a mopar power steering car around with the belt removed.
From my experience, the only time you really need one of the fast ratio manual boxes is if you slide the car around. (snow, ice, rain, dirt, road course or ??) The rest of the time, it is just a hard way to build-up your arm muscles.
Now,...onto turning radius, yes, there is a "trick" to get your car to turn around in a "smaller" circle. If you look under the car while turning the wheels to full "lock", you will see that the rearward lower ball joint bolt head "stops" up against a bump formed into the end of the lower control arm.
73-76 LCAs had less of a bump. (this was to allow more travel for the "wader track" single piston disc brakes. You don't need to switch LCAs, you can simply grind-off metal to allow more travel. Keep an eye-out that the tire does not bottom-out on the frame rail. Just a littly metal removed makes a difference, I did this to a few of my cars and now they do a "curb to curb" U-turn in my narrow street, without a back-up.

Here is where you grind, take some metal off the mating bolt head also.
DD
