Just today, I was able to put together the PS hoses that SHOULD work. I have not tested things yet for leaks.
So here goes . . . .
I'll list the part numbers I used at the very end of this post.
My research tells me the PS gear box was SAE thread up through 1979 and then changed to Metric - so keep that in mind.
I have dumb luck. Really I do.
The problem I was running in to was this. I could order a new HIGH PRESSURE hose to fit either the PS PUMP or the GEAR BOX, but the other end would always have the wrong fitting. What to do . . . what to do . . . . .????
As I stated before, I ordered the correct LOW PRESSURE hose to match my 1974 PS gear box. It should fit no problem since the PS pump end just uses a hose clamp. Guy at the counter shows me the part in the OPEN box . . but it's not a low pressure hose. It's a HIGH PRESSURE hose.
However, it has fittings that look correct for both the PUMP and the GEAR BOX. That's the DUMB LUCK part. So their mistake actually helped me find the RIGHT PART that I was unable to find on my own.
I take this mystery part home and the it actually DOES FIT both the PUMP and GEAR BOX, but the metal tubing bends are not right.
I took the parts I have to a Hydraulic Hose specialty shop and their solution was complicated and expensive. They suggested I just bend the metal tubing on the HIGH PRESSURE hose and make it work. SO I DID.
It may not be factory correct but I didn't need to fabricate a thing. I just used my trusty tubing bender and made two 90 degree bends and I was DONE.
The HIGH PRESSURE hose has the correct double flare on BOTH ends. The PS PUMP END has the correct FEMALE nut and the GEAR BOX end has the correct MALE FITTING. I made a 90 degree bend to turn the longer piece of tubing towards the frame. The GEAR BOX end tubing needed a 90 degree bend too. I did a little more than 90 degrees.
The LOW PRESSURE hose stays just like it came out of the box.
Both hoses sneak between the upper frame rail and the inner fender but there is some contact. I will probably bend the lower lip of the inner fender just a bit to create some more room. I'll also put a sleeve around any area where it might rub. I don't want any holes created from friction and vibration.
Keep in mind that your PS PUMP and GEAR BOX may be different than mine and therefore these part numbers might not be correct for your parts.
I have a 1969 250ci Inline six PS PUMP and brackets matched to a 1974 GMC 2WD TRUCK GEAR BOX.
Part numbers
HIGH pressure hose -
NAPA NPS71143
LOW pressure return hose -
Edelmann Power Steering Return Hose 70551
or
NAPA part# 71202