These past few weeks, I've been helping a friend with some upgrades to his 71 Road Runner. I told him about the Mopar Action magazine "Pump it Down" article where improved steering feel can be achieved with simple mods.
I recall seeing his P/S pump before and thought it was a Federal unit. Yesterday he called and said it was a Saginaw unit. This is good because the magazine article only detailed the "shim trick" for the saginaw pumps.
I got there today and saw that he had THIS pump....

This confused me because I always thought the Saginaw pumps looked like a teardrop with the point cut off at the top. The pressure hose fitting was Saginaw, so was the pressure valve inside. Now looking at them side by side, the mounting bosses for the brackets look identical. Is it fair to say that the pumps are the same but the reservoirs are different?

Anyhow...
It had one .015 shim in the valve. We added more to total .125 and found that it was too much. This had me wondering if the pump was some oddball because I've read that some people have up to .140 thick for shims and theirs work fine.

That's about the size of it. TRW/Federal pumps usually have a press on pulley . Saginaw a threaded/bolt on pulley - I think it uses a keyway too. The really dirty one is an earlier unit - more squared off reservoir a later model pump.

The picture below is clearly the Federal pump. The other two side by side had me confused though.

Both of the pumps in the top pic are Saginaw, they changed to the larger housing on the later models. If you get a reman one from the parts store you will most likely get the bigger housing. I take the pump assembly out of the later housing and put it in the older small housing for the correct look.

Thanks...That makes sense!

Hey Greg, careful with the first one you showed, they have been known to blow their top if you remember!

On the Saginaw's the later one on the right is also the reservoir that GM used.

I'll bet it is okay with the flaky black paint and layer of grime!
The chrome ones are trouble!