try 276/276 but in 4 degrees earlier so it sees the same closing event as the 272, It should add some power up top but not lose anything measurable underneath.

Stroker 101, when the displacement goes up a larger % than the port area...it's far tougher to get enough air in at high RPM to keep the power high than it is to get it out. A longer exhaust event pretty much goes out the window if there's not enough pumping efficiency up there anyway