I have searched around but I can't find the answer to what is probably a simple question. I want to replace my steering gear with a quick ratio box, and I found the posts about he NAPA box. I went to my local NAPA, and sure enoungh he has a 2.5 turn box for 169.00. I got curious about this and went to the Year One site, and there is a lot of text there about 4 bolt versus 3 bolt mounts, and 3/4" input vs. 13/16" input, as well as flat vs. not flat. I went and looked at my box, and it has 3 mount holes, but the wheel goes 3 turns lock to lock, which seems to contradict the information on the Y1 site. :confused: Help! Has anyone put a NAPA box on a 67 with a small block and power steering? Did it work? Did you have to change anything like the coupler or the hose fittings?

Any help would be appreciated.

Sid

Original Saginaw power steering gear housings had four mounting bosses. Passenger cars only used three. Trucks used all four mounts (or a different combination of three mounts.) Later passenger car housings were modified to only have three mounting bosses. All GM passenger cars from the mid 1960s all the way to the Caprice vehicles in the late 1990s used the same three mounting bosses.

The fourth boss was removed from passenger car gear housings sometime in the 1970s (as I remember) because it was not needed. It reduced weight and cost. It remained on some truck housings where that fourth mount was needed.

I would suggest that you go to www.corvettefaq.com/A-car.asp (http://www.corvettefaq.com/A-car.asp) and download the following paper. A-Car Fast Ratio Upgrade Instructions - 6 pages. It explains all of your questions.

Thanks for the link to the faq, but I still have a problem and was hoping for some help. The box I currently have on my car has 3 mount ears, a 3/4" input, 3 1/4 turns lock to lock, and here is where the problem comes in, the pitman arm shaft is 1 1/6" diameter at the top of the shaft and tapers outward.

The new gear has 4 mount ears, (no problem) the input is 13/16" (I am assuming that the coupler sold by Year One is also 13/16" and will fit, so this is ok also), and 2 1/2 turns lock to lock. The pitman arm shaft is 1 3/16", or 1/8" inch bigger in diameter at the top of the shaft. My old pitman arm will not fit.

All the info I can find says that the pitman arm is the same for all of the steering boxes. Mine is not the same, so much for that claim. Any ideas about what pitman arm I need for this box?

During the 1970s, Saginaw came out with a lower cost power steering gear called the 605. It had an acme screw thread inside the gear instead of recirculating balls. It also had a smaller diameter pitman shaft (and therefore, a special pitman arm.) The gear is easily identified by its round aluminum side cover that is held in place by a round wire ring.

The high volume Saginaw model 700 and 800 gears had a somewhat rectangular aluminum side cover with four bolts (one in each corner of the cover.) All Saginaw 700 and 800 gears had the same size pitman shafts.

The 605 gear was used on some GM A-cars and not on others in the same model year. I don't remember what A-cars got them or why. It may have even been certain assembly plants got the 605 gear. The gear was less expensive but it had more internal friction (i.e. acme thread instead of recirculating balls). It soon fell out of favor by the GM Car Divisions and was not used in production for too long.