Timing- what would one tooth offset

If I was off one tooth on my dizzy, how many degrees would my base timing be off. I am tring to time my car an it just doesnt seem right when I try to advance it to 12 or 13 degrees. By the way the spout is out. I have had some one (a dumbass) tell me that one tooth equals about 25 degrees but if anyone knows whether that is BS or not I would appreciate it. I am looking for a quick answer before I start doing the dizzy pull and re-align.


CB
 
Been there & done that...

One tooth off won't do anything except make you twist the distributor farther to get the desired results. Mine was off one tooth and it put the TFI module right up next to the thermostat neck when the timing was at 14 degrees. Other than make it awkward to time, it didn't do anything negitive. As long as you can get the marks to line up when you use the timing light, it doesn't matter.