power steering gear box from newer model

[Olden Days]

I just picked up a 71 frame for my project. It is minus the steering gear box and the arm that bolts to the bottom of it. (I dont know the name of that arm). I understand a later model year gearbox will work up to a certain year. Will the later model "arm" also work or do I need one from the 67-72 era?

[Longhorn Man]

I think you need the later arm, but I am uncertian.
If you are getting a junk yard unit, then you can get the arm and it would probably cost the exact same anyways.

[shadetree]

The latest year is 1981. The arm is called "pitman arm", and the later arm will work. One reason to use a "later" gearbox, you will gain a quicker variable ratio gearing. It will be a little quicker in its' turning, making your truck a little more fun to drive. Ain't Chevies nice? This swap isn't even feasible on those lesser makes. hehe

[Olden Days]

thanks for replying,
Actually I was wondering if the arm (on the later model) was the right length so the steering would not be out of kilter

[shadetree]

It is interchangable with the earlier arm.

[Olden Days]

I dont type fast enough I didnt see your reply before the last post.
Yes, having fun driving is what I am after

[72c5]

I have the same question as Olden Days did. I have a 72 2wd Blazer, and was looking to tighten up the steering.........so the newest I can go is '81? That is still pretty old, the bone yards around here crush anything more than a dozen or so years old.......sure something nice like a '95 or '00 wouldn't fit?

CPP? Chevy Performance Parts?

[hgs_notes]

A newer box will bolt in, but you would have to change the power steering pump along with the box because it has the o-ring style hose connections. I'm not sure how new you can go with that either, might just be to 87.

HG

[337]

The latest year is 1981. The arm is called "pitman arm", and the later arm will work. One reason to use a "later" gearbox, you will gain a quicker variable ratio gearing.

I looked up the part numbers and they are different - probably because of the quicker ratio.

Has anyone actually done this swap?

i just got a 72 gear box from a junk yard.
I will take it back if the newer gear box will work.

[337]

if i do get the later box...

do i pick up the power steering pump and bracket from the donor truck?

or

do i use a power steering pump and bracket from one of our year trucks?

[Tx Firefighter]

All you do is unscrew the fitting in the back of your power steering pump and screw in one from an o-ring type pump. Then use the later model lines too. The fitting takes a 1 inch wrench or socket.

ON EDIT: I don't know where this 1981 cut off year came from. These trucks were the same through 87 and 91 on Suburbans. On my 72, I used either a 90 or 91 Suburban steering box with pitman arm, hoses and everything. Like was said above just change the fitting in the back of your old style pump to match the newer style hoses.

[337]

I don't mean to beat this issue but here's my plans:

take back the 72 gear box.
get a 73-81 gearbox to be safe (these years are plentiful and cheap in the junkyard).

I current don't have a ps pump/hoses/bracket - pick one up from the same truck(73-81)

install it on my truck.

correct me if you see something wrong. i'll be going back on Wed.

[Tx Firefighter]

What I said about using the later steering boxes is not hearsay. I have done it multiple times. The last one I used the 90 or 91 burb stuff because it was the newest one I could find and had less miles on it than the older one would have.

On your current plan, the problem will be the ps pump. In 73, GM changed to the longer style of front accesories. The pump, pulley and brackets are different between the early (thru 72) and late (73 up) styles. You have to either run the short style pump to be proper, or change the whole deal over to the later style.

You need to first determine if your truck has a short or long water pump setup on the engine. Stock would be short, but many of these trucks have been converted by now.

Early style, like proper for these trucks, used the alternator on the driver's side of the engine with short water pump. Later 73 up style puts the alternator on the passenger side of the engine. It also uses a different water pump.

[Tx Firefighter]

This is a picture of the later style of ps pump and brackets like you'll most likely find on the later truck. Notice the pulley is pressed onto the pump, rather than held on with a nut (there were VERY few long style pumps with the nut type of pulley, mainly, ealry 73 trucks, which were oddball).

Remember, if you use this style, you need the right water pump and alternator brackets to mount the alternator on the right side of the engine. The water pump and crank pulleys are also different. It's an all or nothing deal.

[337]

Sounds good.

1. Then I'll find the newest gearbox i can find.
2. Just buy the correct ps pump for our trucks from a parts store.
4. Change the o rings if necessary.
5. Buy lines to match the gearbox year.
6. Look for a bracket/pulley for our trucks since i'll use our trucks ps pump.

I don't blame you if you want to slap me around a couple of time already.