Hot tip. When it comes time to reinstall the pump, get it into place and insert the return line into the pump, tighten the nut and bolt (allen head bolt works really nice here) then pry gently up levering against the crankshaft pulley and the bottom of the pump while you tighten the two nuts in the oblong holes. If you don't seat the return line oring before hand it will surely get cocked in the opening and tear the oring when you tighten the other bolts. Trust me, I've screwed up two of them over the years before I learned this valuable lesson. It is not fun the finish up the job, start the engine and watch coolant piss out the hole.