there is a guy here in town that is making 480rwhp and 515rwtq on just the 2.76 and 4 piece idler kit. with a tune from amazon. exhaust is magnaflow off road x and catback
When you say stock Eaton I assume you mean not ported? I think around 480 is as high as I have ever heard without a port job. I was at 479 before the port. If you are talking ported blower, Trey193 puts down about 540, that's about as high as it gets, he's got some sorta freak on his hands.