Mechanic In Va

[1980SCINVA]

I need to get a second opinion on my 1980 911 sc I rebuilt the motor a few months ago and now my car is loosing power and backfiring more than usual. I had the top and bottom end rebuilt and my mechanic who put my engine in said I need a aar valve and maybe a wur as well. He seems to think the problem is in my cis. I'm not so sure? My car will cut off some times when it is not in gear and I can hear this clicking noise coming from the relay under my passenger seat. I replaced it and I still have the problem just want a mechanic who is recommended on this site near Richmond Va to take a look at my car and see what I need to do..
thanks

James