John they all seem to lose power with any incline, thankfully my Fordor has a ruckstell and thats not a problem.
yes 40 seems low 50-55 is a good reading for compression, that being said I would pull your valve covers and make sure every thing looks good there. More than likely like mine I had a very worn cam and the lifter or "push rods" worn down and "dished" as well.
Also check that your rear drums are clean and properly adjusted, it's a real pain adjusting those brake rods and getting them just right
