Help needed. Engine misd

[Fred2016]

My wifes 98 5.7 tahoe developed a miss and loss of power. Had the codes checked and suggested repair was air filter replacement. Didn't help. Noticed a loose clamp on the flex hose going to the throttle body intake. Ran much better after tightening. Still has a little miss. The gasket on top of the throttle body between it and the plastic breather looks worn out. Thought maybe replacing it may help. Any ideas on what it's called or where i can find one? Also noticed a sound from the dist cap. Sounds like sparking or clicking noise. Help?

 

[#1taho]

Start with cap and rotor.