New plugs?
#2
How many miles, when were they changed last, if you know? Your question doesn't really give anyone any idea of any trouble you have other than a new intake gasket? Is it running poorly still? What year make model? Details are important, they help other members figure out what you have going on
#3
Sorry
Yes its a 98 F-150 XLT Lariat with the 4.6 Triton motor in it and has 198,00 miles. The plugs are only a month old. I replaced coil packs, plugs and wires and had the leak in the intake manifold gasket fixed. It's running good you can't hear the misfire like before it was fixed but still just feel sluggish.