I'm using the stock "p" series gm pump that came on my 2013 avalanche engine. pretty much the same pump that's been used for years. I did rebend the return line slightly to clear the steering box. It really wasn't a big deal just tweaked it a little tighter to the pump. I used an o ring to an #6 adapter on the pump and an inverted flare to an #6 adaptor on the box and connected the two with 36 an high pressure power steering hose. The teflon stuff with the stainless braid and field attachable aeroquip fittings. The steering works just like stock.
Do you remember what size the inverted flare fittings were at the steering box?