You’re referring to a remote reservoir right? It depends, but it’s not necessary. The hydroboost itself just needs a low pressure return plumbed in, just like a Saginaw steering box has a low pressure return going back into the reservoir
I run a remote reservoir but you can find a hydroboost truck at any junkyard. Assuming you have power steering, swap the hydroboost pump can onto your existing pump. The hydroboost can will have 2 low pressure returns. One for the steering box and the other for the hydroboost