'71 Buick GS Steering Upgrades

I have a '71 Buick GS that I am wanting to upgrade the steering. First off I need a new steering gearbox to at least clean up the slack I have. Second off, I want to decrease the gear ratio. As of now, I do not know what ratio would come with a factory 71 GS or Skylark- if they're different. I am looking to get somewhere around 2 turns to lock. Maybe a 12.7:1 but Depending on the price I would entertain the idea of a 10:1 ratio.

Any suggestions of brands or ratios that are reliable?
Any idea if a Cardone 27-6550 would work?

I am also curious if I would need to change the pump or not to give it more resistance or not.

Disclaimer: I am not worried about rebuilding the gearbox as most of the car is not numbers matching as I've replaced or rebuilt anything that rotates on the car.

 

Forum member CARHEX1 provides a steering box replacement or rebuild service. I've used his service and recommend him. Check out the link below.

http://www.v8buick.com/index.php?th...teering-box-2020-pricing.353840/#post-3022765

 

x2 on Carhex. Quality work and excellent customer service.

 

The unit you listed will require either hybrid hoses (not a real issue on the return side) or the adapter inserts to go from o-ring to inverted flare lines. You will also need a new rag joint as that one uses a different size than the factory 71 uses. I put an 87 GN quick ratio on my 70 Stage 1 and it uses the same power steering pump. It is a firmer feeling box than the stock one-finger steering of the original. I put a 1969 Chevelle quick ratio in my 71 4-speed car and it is quicker ratio and everything bolted up like stock.

I like them both and they are about 2.75 turns lock to lock. Old was at least 3.5 lock to lock. I wouldn't hesitate to put either on my car. Some folks claim the GN box will limit turning circle but they steering arms still hit the lower control arm at full lock so I don't see how that can limit my radius.

 

I have the Chevelle box, got it at Advance. No muss, no fuss, everything bolted right up. Livens up the sloppy steering.

 

I used a 96 Jeep Grand Cherokee box from the wreckers that had a 12.7 ratio with, a nice road feel and the correct stops for full turning radius on a GM A body. Same thing as above, for the GN box, it required a different rag joint and hose connections. Not a big deal compared to the improvement benefits. I used it with the stock 71 PS pump and it ran perfectly.

Tom

 

96 wrecker Jeep Grand Cherokee 12.7 ratio
box with high pressure hose adaptor

 

The Jeep Grand Cherokee (JGC) box is practically a "gift" from the OEMs to owners of older A-bodies.

It's near-perfect.

I've got three of 'em, and someday I'll actually install one in my 'Camino.

 

I have used the 12,7:1 AGR box in some cars. You can order them at Summit. They work well.

 

I also suggest Carhex. I had Hector rebuild and upgrade my steering box. Easy transaction and great work. No issues with it at all.

 

I have heard of people putting the 87 GN gearbox on there. I will either end up getting one of Hector's boxes or a GN box. Whichever ends up being cheaper.

Thanks.

 

The GN box will result in reduced turning radius due to different internal stops

 

People keep stating this but I put a GN box on my 70 GS, the steering arms still hit the lower control arm at lock in both directions. How is this reducing my turning radius?

 

Same. Haven’t had any issues. I did have to modify my bump stops because of the ridetech lower control arms I am using. I am going to have to take more off over the winter.

 

Very interesting. If the arms hit the stops, that's a great argument.

Jim Shea' s (Saginaw steering gear engineer) info shows the original MC/GN box (G-body) to have 39.25 deg of travel (left and right) which is less than the original GS/SS/442/GTO box (A-body) at 43.5 deg travel.

 

I'm guessing that there might be a measured difference but not one that is functionally relevant.

Using a clock face for reference since all of us oldtimers can visualize time, the factory 71 box would move the minute hand from straight-ahead (noon) to 21.75° in either direction. That's equivalent to the minute hand at 11:56:23 and 12:03:37 on the clock face.

Taking the GN box with the "reduced" sweep of 39.25° on the same noon clock face, the minute hand would sweep 19.625° in each direction. That's a comparative equivalent to 11:56:44 and 12:03:16 on the clock face.

The difference between 39.25° and 43.5° is only 4.25°. That's the difference between Noon and 12:00:42 on the clock face. Split it in half on each side and you've got an amount of difference that possibly doesn't interfere with the useful turning radius with the tolerances among the pitman arm, steering arms and steering gear box.

 

69 Chevelle SS Quick Ratio box , in stock at AdvanceAuto. Direct bolt in...it is what I installed in my 70' Skylark.....very happy with it...JIM

 

I used that one in my 71 4-speed car. I like them both. That box is really easy to turn, one finger. The GN box has a firmer feel and takes a little more effort. Both are good, depending on your desired outcome. Both really tighten up the turns lock-to-lock.

 

Well actually the sweep quoted is that amount both left and right. So the A-body box sweeps 87 deg total. I think that was unclear earlier.

Like Larry mentioned, the diff may be in the longer pitman arm, or the diff is so small as to not matter