top end miss

If i give the car more than 3/4 throttle or above 3500 rpm's the car starts missing,popping and struggling.I gave it a tune up with the MSD cap and rotor kit, MSD streetfighter wires and autolite plugs. I also dumped some Seafoam fuel cleaner in the tank and changed the fuel filter.The only thing I could think was its either the coil, ignition or the spark plug wires cause they dont have the 45 degree boot, they are straight and pretty close to the headers but it didnt start running like this till about a week to week and a 1/2 after the tuneup. ANY IDEAS??

Thanks for the help guys. It was the #1 cylinder spark plug wire. It was melted through and arching on the header at higher RPM's. That was a waste of MSD wires, Back to FORD RACING wires I go.