If your truck takes AC 41 spark plugs, the 44s will be too hot. The 41s seem too cold, but if that is the correct plug, Ok. A step or two hotter, 42 or 43 would be all right, but check the color after running for a while. I agree with others, that it sounds like your hill trouble is fuel-related. Aside from fuel pressure, you need to check fuel flow from the pump- usually a pint in about 20 seconds at idle speed. More is better, a little less may still be all right. Laurence mentioned a vacuum check- if he means vacuum check on the suction side of the fuel pump, yes. I don't remember the level, but it should go pretty high at idle speed, probably above 10 "Hg.
Harvester
