For timing try this. Get a vacuum gauge and warm up the engine. With the car in park/neutral Check the vacuum reading. Start moving the distributor to get it as close to 20" HG at idle.
The carb is either over or under fueling the engine. (I hate Holleys BTW) If it is a vacuum secondary carb, make sure the butterfly over the secondaries isn't set too loose and causing the secondaries to open too fast.
Setting up a Q jet is pretty easy and once set it stays rock solid...The holley you have wouldn't be a 780 would it?