Where do I start?

The car was running ok before I went and backed off the preload a 1/4 of a turn making it 1/2 turn total. I will check the plug wires again and the coil is fairly new. I broke in the cam by running the motor at 2200 for 20 minutes on initial start up. The cam was degreed and was put in straight up. As far as dropping in the distributor gear, I have no idea if its on the right tooth. I dropped it in while the motor was at TDC and when I put the distributor in where the rotor is #1. Since the car was running ok to start and things have now gone wrong pretty quickly things were right and now they are not. What would cause that? I am having bad feelings but I plan on first removing the valve covers and putting the additional1/4 turn back in on the preload. It would be great if thats the issue. Other than that I will most likely pull the distributor and the wires and re install them step by step and see where that takes me. Hopefully later today, if not today tomorrow since I am off.