fuel economy or mileage,pick one.10-12 initial is good for that era with a stock ish engine.34 total is probably ok.make sure vacuum advance is working as per stock. HEI was available in 74.check plug gap and do not use more than 35-40. set everything else to factory specs. Dual exhaust helps these cars.make sure the ther mac is operating properly. Check base plate of carb for loose screws.check battery and charging system and belts.just a thourough standard(deluxe) tune up.
check cap for white residue inside.dont use a cheapo cap or rotor. use good wires.Check timing chain slack if higher mileage,,,they had plastic cam gear that retarded the cam when worn and the chain also stretched a lot back then.