i have a 1987 4wd 22r with 128000 . runnjing downhe road on fairly level terrain it does great. when you go uphill sometimes it climbs right up and other times the more you mash on the accelerator it runs slower. i have checked my timing, have replaced a few vacuum lines and checked the carb shafts and mounting and cannot find a leak. could it be the carb itself?

 

I have the same problem. Curious what size tires are you running?

 

running firestone destination at 31 10.50 15.