Hi from the Dancing Wolf

I have a 1970 Duster I restored from a frame body donation it took 6 years to find everything the motor I put in it was 318 stock but it doesn't have a lot of juice I found a 73 340 that I am going to rebuild also have a set of 302 heads I was going to put on it or should I stay with the stock 340 heads and what about cams want to keep it as a driver but would love to have a little more power I understand they backed off the power in 73 as apposed to 1970 340 any suggestions?: