08 08 2007 - DOVER - You be the judge of which is the better balancing act: Grant Sizemore on his unicycle, or the way the Durant senior balances football and academics. A senior left tackle with a whopping 6.28 weighted GPA, Sizemore will contend for valedictorian honors. Among his senior-year courses: advance-placement classes in physics, calculus, world history, English literature and environmental science. And like any proficient tackle, Sizemore can master a block, even the small, multi-colored ones. At a recent visit to the Times’ downtown Tampa office, the aspiring pre-med student solved the Rubik’s cube in less than two minutes. BRIAN CASSELLA | Times