84 Chevy Blazer 4X4 power steering prob

My dad had this vehicle and had the diesel engine replaced with a gas
engine.

I am trying to replace the power steering pump, because the one that
is on there only has one return line and needs TWO return lines as
come with the original Diesel engine setup because it has the Hydro
Boost pump for the brake/power steering.  I cant find the power
steering pump to fit it that has the reservoir on the pump, like the
one thats on it (one return line) to replace it with the new one with
two return lines.  Parts houses have pump that says "with reservoir"
but it has NO reservoir on it ??????????????