18,000 orig. mile 318 build

Headers , intake carburetor a better cam , maybe cut the heads a bit to bring up compression a point or 2 , you should be good to go . 318 is a good engine , they just choked it from the fatory with small carb , small valves exhaust and intake manifolds . MY 318 was quick back in the day with those few changes , it's a good starting point .
And don't forget to change the timing chain , those plastic gear setups break easily .