Manual Steering Box

[Greg Reimer 7376]

In my years of A bodies,I learned a thing or two. In the world of 64-72's, the pittman arm is dimensionally the same, even the part number forged into it is the same. these are forged, not cast, for obvious reasons. The difference is that the 66-67 Pittman arm has a larger diameter tapered hole at the drag link. The 66-67 drag link has a larger diameter tapered pin at the end of the drag link. '64-65 and 68-72's will interchange perfectly.Make sure the drag link for the car is the correct year for that series, 64-65 66-67, or 68-72. The length will vary. If you put a 66-67 drag link on your 68-72 and try to compensate for the length difference with the tie rod adjustment, you will have problems.You might get the toe in and straight line ahead adjustment just right, but when you try to steer the car, the geometry goes out the window and the two front wheels won't even begin to follow each other, poor steering, tire wear and noise will occur, and it will not be obvious right away as to what caused it. The swivel joint on the drag link at the pittman arm joint is smaller in diameter than the 66-67,so noticeable looseness there will also be the result. Just make sure that the Pittman arm from the steering box and the drag link are the correct year for the car. I don't know if the S-10 truck Pittman arm dimensions are the same as to its length as the 68-72 Chevelle ,but if it's not, that same geometrical issue would surface. I bought three manual steering Pittman arms at a swap meet once for $20 each, got them home, they all had the same factory part number, but the small end dimensions of the hole for the drag link were not all the same. This stuff is starting to be available from OPG and other Chevelle restoration outlets. Just don't accidentally crossbreed a bunch of parts and create a mess.

[njk53]

The more I read the more I am thinking the steering box - pittman arm interface on our car is the problem with the steering effort. I know we have a heavy car but the steering seems to be abnormally hard. I am going to do some more homework to see what part number pittman arm is on our car. I do know for a fact the steering box is out of a S-10 pick up.

[FED 387]

The GM part numbers for a 68-72 Chevelle pitman you are looking for are as follows:

NON power steering----------- CAST # 5679206
-------- PART # 5679207


WITH POWER STEERING ----- CAST # 5679208
----- PART # 5679209

The part number for a manual steering box is I believe GM7842236 or some times referred to as a #525


Hope this helps--FED 387

[Hacksaw]

Also there are two types of s-10 boxes. I think the one with 4 bolts on the top cover is the popular one for swaps.

[Travis Miller]

It must be kept in mind that two parts with the same casting numbers can be different. The difference comes when the part is machined for different applications. That is where the part number comes into play.

[Greg Reimer 7376]

Travis brings up a good point. Casting or forging numbers are for the raw part. It gets finished up as necessary for whatever application it ultimately was installed in. I touched on that with the forging number on the manual steering Pittman arm for the 64-72 A body cars being the same, but the small hole was sized differently for the 66-67 drag link,since the tapered pin on the drivers side of the drag link is larger on those two years only. The forging number is the same, but don't try to use the wrong part on the wrong year car. If someone has a GM parts book from that era, that would bear this out. Also, the older GM A body manual box might have more turns lock to lock than the S-10, that could be a factor. After you get it figured out,come back and tell us what you found!

[njk53]

I definitely will let you guys know what I have come up with. Thank you to all who responded.

[john kunsak]

Vega box from flaming river. you can buy it with a pittman arm custom made for your application since the pittman shaft is smaller than the a f & x body manual boxes. Saves 3-4 lbs over standard manual box. Ive used these for 30 years on ss/e,gta 3600 lb 9 sec. Cars. big block wheelstanders, 140 mph. Handle like a suburban on top end. Call rocco at flaming river