My 76 had sat for a while also I did pretty much same as you maintenance wise. I did not pull the thank and clean it that is were my problem was. I could put new fuel filters on and it would run fine for a few minutes then sputter and die. My problem was junk in the tank kept clogging the filters it only took a couple minutes to clog them tight. Hope this helps some also download the fsm from xenon that should help with hose routing.