Redhead powersteering box question

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Well-known member
Sep 2, 2021
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Hello! My car (73 Coupe 302) has a redhead powersteering box (with the quick ratio steering worm deal). I was told the box is a saginaw and the fittings on the box M18x1.5 (pressure) and M16x1.5 (rerurn).
My pump is a tuff stuff 6176B (also a saginaw) with a 5/16x18 sae threads.

Where in all that is holy do I get lines made? Or I can make them myself.... just don't know the fitting type (do they have o rings? I looked online but became overwhelmed with options). My car had thus entire system missing so I have nothing to compare it to.
So that's sweet.

I can make my own lines if I know the fitting type. I even have the machine to make high pressure lines (the kind that use the machine to crimp steel fittings to high pressure line).

I really want to be able to steer my car, any help is appreciated!!
Kick ass!
Hi Manny,
Well, I can't be 100% certain of the inlet and return port sizes, I don't seem to be able to find that info right now, but of the 5 PS boxes I've rebuilt myself, none were metric threads on those ports. Unless they have been re-machined by RedHead and converted to metric, that would be the only reason I can think of.
I'll look further for the thread sizes and get back unless someone else has that info. I can tell you that the inlet is different to the return.
I'll continue to check the hose sizes. As for lines, NPD sell them in SAE sizes.
found it, Before 1981, the HP inlet was 11/16" and the return was 5/8" flared fittings. After 1981, they switched to metric.
So, it all depends on which year box you have. I'm only conversant with pre 1980.
Hope that helps.
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Any good hydraulic hose shop should be able to make you up the proper hose with correct fittings. Too bad you don't have hoses to act as a template, though....
Any chance you could post a close-up of the ports on your steering box?

Also, Summit racing has a ton of adapters, but it is difficult to search through them.
Thanks all for the help... here is my setup in my car. Please excuse the crummy pics. I circled the port for the pump (5/16x18 thread). Any idea what my lines should look like or what fittings I need? I don't mind making my lines.... just have no idea what fittings I need to order.

Thanks all again!


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That looks like regular old inverted flare ports. Stock hoses should work.

I’d probably take some acetone on a q-tip and clean out those ports.


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If that's the original steering box it doesn't have metric hose fittings. The metric line fittings I've seen have a crimp in the line and an o-ring, not an inverted flare.
That looks like a GM style Saginaw pump.

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