So back on track here with the caviation issue. I ,badly, drew up some piping plans. which would be best or if someone has something better let me know. All of them put the pump on the floor of the boiler shed. And all supply piping will be 1.5" pipe and all fittings will be butt weld fittings. All return piping is 1" unless you guys think i should step that up too. Either way all fittings are butt weld fittings. #1 basically just keep the same supply and return ports just bigger piping #2 use both supply and return ports. Return feeding into the current return port mainly. #3 use both supply and return. Return feeds into a tee to help split the return between ports. And if you guys want to draw your own piping if you think a different way is better here's the shot I used.