keyway or press fit--how to tell?

[absintheisfun]

I have used the search feature (thinking this was a common question) and searched deep into 2006's posts with no luck...

What is the give-away that identifies your power steering pump as one or the other?

I did some googling and some info, but don't know how much I trust it. What I read was that Keyways will have a nut on the center of the pulley, and pressfit will have an allen-head. Any truth to that?

Thanks!

[David Pozzi]

Keyway uses a smaller shaft & has a nut. Usually has a male outlet fitting. Around 1974, GM switched to a larger shaft press on pulley with Allen hex in the end.
Only the pulley end of the shaft is different & the outlet fittings can be swapped as needed.
In the early 80's the outlet was changed to a Metric "Saginaw" fitting with an "O" ring seal.

[Gitter Dun]

What year power steering pulley and from what car? If its pre 74 it will have a key way and Kragens(well now Oreilly's) carries a pulley puller for about $40.

[absintheisfun]

What year power steering pulley and from what car? If its pre 74 it will have a key way and Kragens(well now Oreilly's) carries a pulley puller for about $40.

I have no idea. I converted my 63 C10 to power steering and got a pulley from a 70's C10, but have absolutely no clue on specific year. The pulleys don't quite line up right so I'm going to get a front runner that is designed to work together.

[SLO_Z28]

1974 is still the bolt on style pump. I think 1975 was the first year of the press on style, but im not sure on that.

[MonzaRacer]

key way=bolt on
press fit= well self explanatory

[absintheisfun]

Okay, So I'm sure that this is a keyway, but because I want to make absolute certain before I spend the cash...could anyone be so kind as to verify this is indeed a keyway?

Thanks!