I'm still trying to decide if I should replace my cap and rotor on my 1995 Z28 that seems to run as well as ever.Is it just a good idea to replace these items,or will I actually gain performance that I didn't know was missing? It starts right up in about two seconds,and still over powers the size 285 back tires,but at around 2000 rpm,there's a buzz/vibration I can feel through the chassis until about 4000 rpm,even though it is pulling hard.This is not my daily driver,so down time is not an issue.Could the buzz be periodic missfires,or an imbalance that came from nowhere?Advice on a brand would be appreciated too.Choices are BWD,Accel,MSD, or what? thanks,edman

 

That doesn't sound like a misfire to me.

I would not replace the cap and rotor unless there was an actual problem that you diagnosed with the optispark. When you do replace it, replace the entire unit with a factory optispark.

Don't get an aftermarket optispark.

 

If it ain't broke. don't fix it. Your problem could be so many things, its hard to say what. OEM on the opti, when the time comes.