I wish I could offer some specific suggestions but I can’t. I do think you might want to checkout Batesville, IN. There’s 2 exits off I-74 and I think the 2nd one has a few tavern type places. Also, Greensburg (home of the courthouse with the tree growing from the roof) is bound to have some tenderloin places.
Symmes Tavern in Fairfield has a passable tenderloin. Check out Shapiro’s deli sometime.
I used to stop at an Irish pub on west side of Indy at the Speedway exit. About a mile on the right, they had awesome tenderloins.