How much timing is too much?

[93 Cobra needs input]

I have read alot about total timing on the message board but never really knew how to go about it. So all you need to do if your at the track is pull the spout connecter and read and set total timing on the balancer at idle, then leave the spout out and the cars timing will not advance or use the preset computers timing advance? Sounds like a decent way to eliminate bad timing curves in my factory cobra computer. One question do you lose some power from not having your timing lower initinally then advancing? Thanks for any replys.