New battery, Higher idle

I installed a 700 cca battery in my GT yesterday and now my car idles at around 1100 rpm's. When I give it gas while idling it wants to hang at around 2000 rpm's for a couple of seconds. Anyone have any idea why this is happening? My old battery that was in the car died and had this brand new NAPA legend laying around so I used it as a replacement. The battery is taller and longer than the battery I took out, but I don't think that would have anything to do with the problem.

No, check engine light is not on. I replaced the IAC valve with a new motorcraft one about 3k miles ago so I do not think it is the problem. The idle would do the same thing it is doing now every once in awhile before I changed the battery. Turning the engine off and restarting it always fixed the problem though. Since the battery swap it does it all the time. When I push in the clutch or put the car in neutral idle stays at around 2 grand for about 20 seconds and slowly drops down. Before it would drop to around 700 rpm's but now idles at around 1100. I have made no adjustments to anything.

Since I have been driving it the idle is getting close to more normal. The old battery I think was going bad for awhile. It used to turn over slower and take a second to start. Now when I turn the key it spins over faster and starts instantly. I am hoping its just a matter of the PCM relearning the extra charge and it will go back to normal soon. I hope anyway.