Spark retard at Idle

my friend just put in a cam and ported and polished his head. For some reason the car has 1-3 degrees of spark retard at IDLE? I do not understand this at all, then its ok through the middle rpm's then he has like 10 degrees or whatever up on the top end. Is it possible like the opti was put on wrong or something? We have no idea why it would do this. Anything I can look for in the datamaster software or anything?

Timing gear off a tooth or maybe the opti on wrong if you have a 95-97 model. The latter is more likely though.

I have had to increase the closed TPS timing in the PCM by about 7-10 degrees in the 800-1200 rpm cell to get the car to really idle really good after a cam/head swap. Stock is set for 20 degrees btw. So the opti has to be installed on the wrong pin slot or the timing gear is at least two teeth off. That is, if your retard is caused by too much timing.

Any other thoughts on the matter?