Hydroboost steering box interchange

[1FaastC10]

i have a friend who just bought a 77 C30 with a hydroboost system on it. it needs a new steering box. i have one that came off of an 81 C10 that came from the factory with a diesel in it. will the boxes interchange without a problem?

[68 Stepside]

I think *think* the 81-up boxes have metric threaded holes....If not, I think it should swap out.

[Captkaos]

Because of the thread, the 81 box won't "bolt" up. He would need a new pump as it is dependent on the pump. As for the differences in a Hydroboost vs non-Hydroboost gearbox there are none.

[1FaastC10]

what about the box wont bolt up? i was going to put an 82 box on my 77 frame (the one that was going to be installed under the 82) so that wouldnt have worked either?

[Captkaos]

It will bolt up to the frame, but the power steering hose ends won't bolt up. Pre 1980 are standard thread, and Post are Metric. I have a post 80's box on my 73 frame, and I am going to use a metric reservior and hoses. That is the only difference. It will work, but you can take a working box from a post 80's and remove a non working one from a pre 80's and not have to go to the hardware store to get the metric pieces. You would have to rob everything connected to the power box.

[1FaastC10]

ok, so in short, my box wont bolt up with no other mods necesary. that's what i needed to know.