88 yj dieseling after timing set for smog?whats your btc?

what are you guys running your timing at my jeep never diesled like this before they changed the timeing for smog now its 9btc it was at 28 btc!!!
what is safe to use for a better performance without dieseling?:banghead:

o.k. so i talked to the shop today and they said it could be either 9 btdc or 16 btdc for high altitude anyone know how to detemermine? or is this for when you live at a certain elevation the guy at the shop said it depends on the set up of that perticular jeep?