Maybe we should start with the basics. These engines are actually fairly easy to make run well if you can take care of 4 things
1. Fuel - its the fuel clean, filter clogged, carb adjusted correctly, carb dirty or clogged?
2. Fire - are the plugs fouled, is the rotor and cap on the distributor good, is the coil in good shape, is the voltage going to the coil correct?
3. Timing - is the fire and fuel meeting at the right time?
4. Vacuum - is there a leak, hose unplugged, hose rotted or missing, PVC or EGR stuck or bad, is the intake gasket good?
I have found if all 4 of these are in harmony and set reasonably close it will run great, if not well, not great
Check these 4 things first, it sounds like you don't have the correct amount of power to get up the hill, the running roughly is an indicator of one of these 4 being out of adjustment
Good luck and keep us posted, lots of helpful folks on this forum to get you running like a champ asap!