Engine still not right after timing set

I'm not the expert, so bear with me. '73 Duster with a '78 (i believe) 440. Quickfuel 750 (vacuum secondaries if I remember correctly) electronic choke.

The timing was off, that was apparent. Bolt on the distributor came loose one day. I've had two people help me try to set the timing but it never quite sat right. I took it to a local shop today to figure out what's going on. After replacing the plugs and setting the time, the guy says he has it started and running but something is still off. I forget exactly what he said but says it might be a valve partially sticking open and would have to take off the headers and possible pull the motor partially out to test compression. He was asking me for the cam card, which I thought was in the car. All I can remember is it was a comp cam, possibly with .4xx lift. I know I have paperwork for the cam that was put in years ago but I'm in the process of moving and it could be boxed up.

I know all this info is rather vague, but what else could cause the engine that has proper timing set but still feels otherwise? Either way I feel like this little tuneup is gonna end up costing me more than expected.