I have 3 of these pumps (gotten for free) and need to move less gpm's from the wood boiler to the load pump and storage when hooked up. I know, i know... I should get the right size pump for the head loss but these were FREE. Two options I think. One- choke down the inlet and outlet to maybe .75" instead of the 1" hole or, two- cut off 4 of the 8 blades on the impeller of the pump. What option do you guys think would give the desired effect? I have about 3.5' of head loss and need to move 8-10 gpm. The right pump would be a 005 or 006 has anyone been inside those and if so what do they do different?