Help with 318

My son has a 1970 318 in his demon. we have a set of 302 heads on it I think the intake is elder LD4B, elder 650 carb, only number I find on the cam is EDEL 955836, I can’t find any spec on it with 323 gears. This thing starts runs out good but will not get out of its own way. So just looking for advice what do you think the problem is with the performance issue. Thanks for any advice. Mike