Heres what I would do if mine.
make sure the truck is getting clean fresh gas clean the tank and replace rubber fuel lines. check the fuel pump for flow and pressure.
rebuild the carb. do not replace it or swap it for a carb at the auto parts.
check the ignition system make sure the vacuum diaphragm is not leaking. twist the rotor in the distributor and release it it should snap back on its own. look for crosion on all the contacts inside the distributor.
replace all the rubber vacuum lines a 1977 has a lot of them. any loose or cracked lines can cause issues. there are vacuum connections at the back of the auto tranny and the vacuum tree usually has a cap on some of its vacuum ports. remove the pcv valve and check its free floating ball in it. only replace it with a motorcraft one designed for your truck.
ohms check your plug wires and replace them and the plugs if needed.
clean and check your battery connections, be sure to check the ground between the negative post and the body, the negative post and the engine block, the mount and bolt from the starter solenoid and the voltage regulator. the air cleaner has vacuum connections under it too.
change the coolant while your at it.
none of this is expensive unless your paying someone to do it. do not peck at this piecemeal work on the fuel system check and repair from one end to the other, work on the vacuum system cahang all the lines at once not just the worse looking ones. once you fix a system it will hold up for a long time.
run the truck for a week and then do a compression test for the record. compression tests can get weird when engines sit a long time.
change all oils and fluids.
after you get it running properly then address the running gear like brakes wheel bearings and service to those systems.
have fun in your adventure. 1977 is the best year Bronco made and is a great truck to leave in origional condition it needs nothing to make it better if left stock.
