1970 Dodge Dart 318 upgrades

If I was the op, i'd have already PM'd you...….
One of the cheapest upgrades.... used 340 cam and a factory cast intake.... and one of the hardest to beat in mild hop-ups for a 318. The "freshening up" the OP talks about would be spent "freshening up the heads". All the cams in China are a pile of mush if your valves don't seal
All the cams in the world would be mush if your valves don't seal,lol.