Steering box input size?

[muddpile]

I'm just gathering parts for my steering swap from rack to box, and was curious what GM used for a spline size and count? 3/4-36 was used on the column end I know, but is it the same on the box end? Thanks!

[Captainfab]

There were 3 different sizes used.....3/4-30, 3/4-36 and 13/16-30 or 36 (don't remember which) Sorry but I don't know which years used which splines.

[muddpile]

Well, I went and checked the box I plan on using. It's got 31 splines and a flat side, leading me to believe it's a 36. I have a Borgeson U-joint that has 3/4-36 input on it, and it won't go on, leading me to believe it's a 13/16-36. Sound about right for a mid-70's 1/2 ton 2wd power box?

[Captainfab]

I've run into the 13/16-36 before, but I don't recall exactly what year it was.....probably in the 70's somewhere.

[muddpile]

Another question. My other option is manual steering (due to the rear engine and an extremely long power steering hose setup and light front). My frame is a boxed pro-street cloned in the front from a 73-87 pickup. Will a 60's manual gearbox bolt to that? Also, what years of front end parts like tie rod, idler arm, etc are the same? Looking tonight I think I might go the manual route.

Thanks!

[Captainfab]

If you want a manual box one from a '69-'87 will be a bolt on, although one from the '67 or '68 may work also. I have one from a '67 at the shop, I'd have to verify that it would bolt up to the '73-'87 frame. Also the newest manual box that I have seen myself is a '74.

As for the other parts, all the '73-'87 C10 stuff interchanges to my knowledge. When I ask for parts for the front suspension I go with a '77.....the year I graduated from high school

[muddpile]

OK, I've got some more parts accumulated. I went and tore the steering box, idler arm, tie rod ends and tie rod off my parts truck, which I believe is a 64 GMC.

Now, it looks like it'll bolt to my frame and work properly, plus it's a low mile truck so it's in good shape. I have a couple questions, however.

-Would adjuster sleeves and tie rod ends from a 73-87 have the same thread?
-Is there anything I need to know about maintenance on these old manual boxes, adjustment, etc?

[Captainfab]

Originally Posted by muddpile

-Would adjuster sleeves and tie rod ends from a 73-87 have the same thread?

I believe they are different......always swapped everything myself. Seems like CPP or someone sells an adapter adjusting sleeve

Originally Posted by muddpile

-Is there anything I need to know about maintenance on these old manual boxes, adjustment, etc?

Just make sure it has lube, and then there's the adjustment on top to take care of worn gears inside.