when I say I modified the reservior on the pump, all I did was added the hole on the rh side like most other saganaw pumps have and used the existing threaded boss/added the correct o-ring seal, nothing special. I think I can just buy an '80's/90's truck pump and get the hole already there. The reason I bothered swapping is because I had 3 good (no more) 3rd gen pumps sitting around.