Quick ratio steering box - what year? 1976? 1978

[Project1970]

Long time no post...heh.

After a few years of driving more modern cars with rack and pinion steering, I've gotten sick and tired of the original 4.5-turn power steering box in my '70, along with the rag joint and the banged up old steering column. I know I won't get it up to R&P levels of feedback, but I'd like to tighten it all up the best I can, and I figure the best way to do that is to essentially scrap my whole existing setup from the box on up. I know the tie rods and pitman arm are all good, those have been replaced in recent history; the box has been resealed and that's about it.

I've searched over and over again and I keep finding conflicting info on what year I should actually use for the steering box. I'm not concerned with keeping the box compatible with the old rag joint as I'm throwing that away, and if I have to I'm not even worried about changing the lines since I'm already running custom ones with the LS1. I know that sometime after 1975, they went to a 3.5 turn lock-to-lock power steering box, but I see some references to some boxes being variable ratio and some not. Variable-ratio would be nice to have.

So...what's the best bet? As long as the output shaft fits the pitman arm and it bolts up to the frame in the same spot, I'm happy with it.

[mikey531]

I have no idea if this would work but I parted out a 1994 Jeep Grand Cherokee and sold the steering box to a guy restoring a El Camino I can't remember the year but he said it was a quicker ratio box and would bolt in.

[SactoJim]

Pulled mine out of a 76......works great and was a bolt in (no metric). Just a quicker box.

[El Jay]

I've got a box out of about a '72 van on my '69. (manual to power conversion)
Even though it's 4 turns lock to lock, it can still be a bit "twitchy" on the freeway.

I don't know what's available, or what would even fit, but if you don't want to change the steering box, a longer pitman arm will "speed up" the steering. Naturally, you'd have to readjust the toe.

For a side note, I put an aftermarket pitman arm "extension" on my VW based sand buggy and I ended up with about 1 1/2 turns lock to lock. It was great for chasing jackrabbits in the desert.

[Project1970]

Hmm. I've done a little more reading and it looks like the '78 box may be the one I'm looking for:

*Power steering hoses are the same between 1976 and 1978 - still flared fittings, so the '78 is not metric
*Pitman arm is the same between 1976 and 1978 - so I won't need to swap that around

But, the steering gear part number is different between the two - the '68-'76 box is listed as 7501, while the '78 box is 7512.

Part of my worry with going with the '76 box - I'll be getting a reman - is that since they use the same part number, it seems like I'd run a chance of getting another 4.5 turn lock-to-lock box from a '72 or older truck.

[mikey531]

Here is the link about using the Jeep steering box in a Chevelle/El Camino

http://www.chevelles.com/forums/showthread.php?t=276344

Read Question 6

[PanelDeland]

Subscribed

[Hart_Rod]

Here are some more threads discussing power steering mods and upgrades:

http://67-72chevytrucks.com/vboard/s...d.php?t=182114

http://67-72chevytrucks.com/vboard/s...d.php?t=224061

http://www.chevelles.com/techref/ftecref29.html

http://www.ih8mud.com/tech/woody/ps-pump.html

[Project1970]

Originally Posted by mikey531

Here is the link about using the Jeep steering box in a Chevelle/El Camino

http://www.chevelles.com/forums/showthread.php?t=276344

Read Question 6

I thought the car power steering boxes won't bolt up to a truck frame?

[schwoch1]

Originally Posted by Project1970

I thought the car power steering boxes won't bolt up to a truck frame?

They won't, the truck boxes bolt on the outside of the framerail and the car boxes bolt on the inside!!!

Mike

[1968SWBBigBlock]

Just take the box to a re builder (if you do not have one close buy Google steer & gear in Columbus Ohio)
When they rebuild your box they will make it a quick ratio - I do not think it even cost me any more

[Lugnut64052]

Originally Posted by PanelDeland

Subscribed

Me too.

[mclairmo]

A good rebuilder can make it quick ratio. I used Lee Manufacturing in Sun Valley CA and they are very good. They build components for lots of racers. They can also rebuild your power steering pump and calibrate the pump and box to work better together. They do it all.

[Sammy]

Staying with the subject.. What kinda cost is involved to have a box upgraded and the pump calibrated? This sounds rather interesting. Who would you look for to do this sorta thing? Speed shop? High end machine shop?

[ERASER5]

I think the '78 is not a "quick" ratio, but a "variable" ratio. It is slow in the middle (small change for going straight corrections) and gets progressively faster toward the outside ( for going around the corner). This a good setup as it is not twitchy on the highway, but handles well in the twisties.