Diners wait for Killen's BBQ to open on a Saturday morning in Pearland, a suburb of Houston. Be bold. That advice from an old boss recently ran through my head here at Posse HQ as we contemplated stepping off the barbecue cliff. We took the step. Yes, we are predicting that Killen’s Barbecue in suburban Houston will be No. 1 on Texas Monthly’s highly anticipated list of the Top 50 BBQ joints in Texas, displacing the legendary Franklin Barbecue in Austin. It shouldn’t take long to know whether that call is indeed bold or just plain boneheaded. The list will…