Power Steering Pump Seal vs O-ring

[Bearhawg]

I started to rebuild my PS pump and ran into an issue. The seal kit I purchased included o-rings and not the square shouldered seal on the pump. I figured one was as good as the other but soon discovered there is a difference. With the o-ring, I was unable to install the pump tank on the pump. The o-ring would not stay seated in the grove around the pump. I tried it will fluid on the seal but it was still too tight to install the reservoir.

Has anyone done the install with the o-ring? If not, where did you find the correct seal?

Thanks!