cap and rotor burnt!

i put a brand new MSD billit dist. in my 87 5.0 2 months ago and just the other day the car started running really rich and little rough at around 2000 rpm in any gear. the A/F guage is pegged all the way on rich now. i noticed that the cap points have alot of crust on them and the rotor does too. also the spark plug wires have a little rust in the boots especially the coil wire. could the cap and rotor be burnt out b/c of the bad plug wires and the reason its running rich is because its not getting enough spark?