Kennyhbh Ken are you running an MSD setup?? If yes check the cap and rotor. The center of the cap probe is carbon and may have cracked off. You will get spark but ugly. Check rotor end for burn and make sure the steel point is tight in rotor cover. How do you have the coil mounted. If it is an
oil filled one you want the coil vertical and if possible not mounted on the motor.
Next would be to check the fuel pressure regulator to too high a pressure. NO more than 5 psi is needed to run a motor. When you start running 6 psi and high the floats start to bounce and cause flooding when driving. Do you have black smoke coming from pipes? If so what color does it look. As others have said, gas is black, blue is
oil, white is water. I would make sure you also that the correct PCV valve in the motor. It could be sucking
oil instead of oil mist in motor. Leave pcv valve off motor and road test add rag to keep oil from sparying on motor and is if spark plugs go bad again. If not we need to check valve and possible blowby from the rings in the motor. May have a bad motor. I have seen bad camshafts and distributor gear problems in Roush motors. Pictures would really help here. Final checks make sure you the the correct gap for the plugs in this motor. Get a spark tester and make sure the spark is bright and strong. If you have a spare plug and vice grips and wire to ground plug you want that nice spark with the motor running. Start with fuel pressure first. Good luck. Rick L.