Ok so after doing my engine swap and changing out most of the parts and whatnot my idle is a little bit off. It idles around 1200 in park when I first start the car and then around 1000rpm at idle in drive. It also seems to surge up and down now and then after warming up. Its not bad but enough to notice and doesnt seem to run very well. It also doesnt throw any codes. Does the car have to go through an idle relearn? I had the battery previously disconnected. Any help to as how I can get this solved would be helpful.

Heres some stats on the car:
-3.4 swapped
-3.4 injectors already checked out
-new maf sensor
-new o2 sensor
-cleaned intake manifold
-pace setter headers
-automatic transmission