cant find miss

I have just about changed everything and my car still has a miss.Its seems to run ok at wide open throttle but at idle or part throttle it misses.When I put my timing light on it the timing is moving about 4-5* at idle I guees from the miss.I have a 750 holley that I put a kit in but I dont know if there is an internal leak or some other problem with the carb.Most of the plugs are black so I know it is running rich.What in the carb would cause this problem?It also has a stumble just off idle.I have changed plugs,cap,rotor,coil,distributor,wires,I also changed carbs a while back with another used 750 vac secondary but I dont think that carb is very good either.My cranking compression is around 180 on all cylinders,which I thought would be higher with 11:1 pistons,is that about right?
Any help would be greatly appreciated.

The vacuum is 9 to 10" and not real steady in park.What in the carb would cause this rich condition?The car starts right up but then dies untill warmed up.Then sometimes it will crank up and run and some times it cranks and then dies like the carb is not right.Is 180 psi cranking compression where it should be with 11;1 pistons 64cc chambers and a 109 lsa?
As far as a vac leak I have checked.I have even changed the intake gasket just to make sure,and the old gasket looked good everywhere.Do some motors sound like they have a miss untill full throttle?I have heard some at the track that sound bad untill the take off then they sound fine.I dont know I'm just asking.

Another thing,can the carb cause a miss?Its a small miss it doesnt pop or cut out real bad just a noticable miss.The car has a rich smell at idle and the plugs clean up some when I take it for a spin.This has been going on for a while and it is driing me crazy.

A good tool for finding a miss is an infrared thermometer. Fire up the engine from cold, and read the temp of the exhaust manifold at each port, a missing cylinder will be much cooler.