As promised, I am posting the result of my swap to NAPA's 2.5 to 3 turn box made specifically for a 1972 Chevelle. A few years ago, I went with NAPA's 1986 Monte Carlo box with Lee Mfg's rag joint and fitting adapters and was never happy with the result. The MC box would not allow tight turns and I personally did not like the road feel it gave. The new box's pitman shaft responds to the slightest movement of the input shaft which the MC box did not do and that might have been a defect. Anyway, the steering wheel effort is easier than with the 1986 MC box but the number of turns lock to lock is barely over 2.5 and is the same as the MC box. The front wheels turn just as quickly now as they did with the MC box for the same steering wheel movement but with less effort. I know some people like the stiffer feel of the MC box (Is this the Close Ratio feel?) but I personally prefer the Chevelle box plus I can use original fittings.

That is good information to have. I still would like to also know how the NAPA box compares to the AGP box in feel.

Would you call the NAPA box feel "slushy" like an original slow ratio box? I'm referring to the feel of the wheel and effort, not the quickness of the steering.

The production 1972 Chevelle power steering gear had a steering gear valve with a 12 to 17 inch-lb setting. It would be like steering with a water faucet valve (very light effort with little road feel). The pitman shaft travel was 83 degrees.

The production 1986 Monte Carlo power gear had a 24 to 30 inch-lb valve (twice the effort!). Also the pitman shaft travel was only 78 degrees. That explains why your turning circle got much larger.

I have no idea why the ride engineers at Chevrolet selected such a light effort gear for the 1972 Chevelle.

I have a lot of information along with spread sheets on the production steering gears for Chevelles (and other cars) of that era. They are posted at www.corvettefaq.com/A-car.asp (http://www.corvettefaq.com/A-car.asp)

Good luck,
Jim

Unfortunately, I can't speak for exactly what parts the aftermarket people are using in the gears that they are advertising for the various makes and models.

so the new one still had the same turning radius liitations as the mc box? and the only difference you can tell is in the effort?

awww...just use a power steering box without the pump smile.gif

Originally posted by Rich-L79:
[QBWould you call the NAPA box feel "slushy" like an original slow ratio box? I'm referring to the feel of the wheel and effort, not the quickness of the steering. [/QB]Yes, the NAPA box takes very little effort to turn the wheels like it was originally. Actually, I missed the original feeling but the box does respond quickly and is fun to drove. I have a 12.5 diameter steering wheel and maybe this eliminates some of that feeling.

FO_FDYFO - The steering radius is now correct for my car and I can make tight turns now. The box does not have the stiff road feel that the MC box had but I could not live with the wide turn radius it gave me. I think I had a bad MC box as there was alot of slop in it that allowed the car to wander on the highway. The new box doesn't do this.

JIML82
I really appreciate all of your help and it is great to have someone with your background offer advise. I haven't adjusted my tierods yet to center the box to the wheels but I did find the center of the box so its a start. I marked the ragjoint with paint and one of the ragjoint pins is straight up when the box is centered, if that sounds right. I take it that centering the box will help to keep the car from wandering on the highway as long as the rest of the steering system is tight.

Our '67 Chevelle had zero road feel. Our '72 Lemans Sport has about 3 1/4 turns lock to lock and has enough road feel to satisfy us. We're putting an identical setup on our '69 Chevelle. These units should still be available in the wrecking yards.

Originally posted by loosend:
</font><blockquote>quote:</font><hr />Originally posted by Rich-L79:
[QBWould you call the NAPA box feel "slushy" like an original slow ratio box? I'm referring to the feel of the wheel and effort, not the quickness of the steering. Yes, the NAPA box takes very little effort to turn the wheels like it was originally. Actually, I missed the original feeling but the box does respond quickly and is fun to drove. I have a 12.5 diameter steering wheel and maybe this eliminates some of that feeling.
[/QB]</font>[/QUOTE]That's too bad because I'd really like some road feel but the NAPA box provides the same ratio & lock-to-lock without the steering limits of the MC box for a much better price than the AGP box. I'm torn as to which one to use. I wish the NAPA box had the stiffer tuning and road feel of the AGP box and I'd be set.

Is there any way to adjust the box to get a tighter feel? I'm a honda tech by day and the racks we use can be adjusted so tight it will hold the wheel. :confused:

Anyone have any comparison to the Jeep box? Jim, do you happen to know what the valve in the Jeep box is rated at, 18lbs or so? How difficult is it to change the valve and who would you go to to get a stiffer valve?