Texas Tech (2-1) at No. 6 Oklahoma (3-0), Saturday at 11 a.m. CDT (FOX). Line: Oklahoma by 27. Series record: Oklahoma leads 20-6. WHAT’S AT STAKE? Oklahoma has lost ground in the AP poll the past two weeks, despite remaining undefeated. Without a significant non-conference win, there is no room for a loss — or even for a bad day. The Sooners need to win convincingly to maintain consideration…