1970 Dodge Dart 318 upgrades

I would not use the old 340 cam even if it was free
closing ramps are way too long for any dynamic compression
SAE timing is 20 79 79 30 with 50 degrees of overlap (at .004 which you can compare with that Summit cam or CRANE) that's a 279-289 seat timing cam
Chrysler timing is more like .008
Howard or Lunati are good places to start looking comp has nothing in this range and others are custom except Hughes