Maybe, maybe not. Indy is obviously making calls for Manning to break the record, so when they're in the red zone they throw passes instead of the normal running the ball plays. Plus, harrison historically does better at home. And maybe I'm looking into it too much, but I think if he breaks the record, he'll make a serious attempt to throw it to Harrison.
Besides, as of late TJ Houshmanzata (sp?) has been catching fire with the Bengals, and in doing so taking points away from CJ, and they're facing a surging Buffalo Bills team. Additionally, Palmer might not start the game, and while I'm a big fan of Kitna, he may be rusty.
I don't think you can go totally wrong each way, but I'm leaning towards Harrison, but that's just me.