Indiana football coach Tom Allen said Sunday that he plans to enter spring football on March 4 with four scholarship quarterbacks: Tayven Jackson, Brendan Sorsby, Broc Lowry and Dexter Williams, who is recovering from a knee injury. BLOOMINGTON, Ind. – Tom Allen made a splash in the transfer portal on Jan. 15 when former Tennessee quarterback Tayven Jackson announced his commitment to Indiana. It was a natural fit for Jackson and Allen, who’ve had a strong relationship dating back to Jackson’s early high school years at Center Grove in Greenwood, Ind. “We had a scheduled time.” Allen said. “He called…