Gene, late stoppage. Tunney-Gibbons all over again. Bob would simply be getting hit too much for too long, very badly outmaneuvered by Gene, and BF's power simply disappeared like magic against quality HWs, including the 203 pound Earnie Terrell. Bobby was steamrolled by the admittedly far more experienced 182 pound Doug Jones, who never took a backwards step. Tunney came in at at an extremely strong 192 for Heeney, his career finale and performance peak. Bob doesn't win a single round for as long as it lasts. I think Gene decks him a few times before a double digit round knockout.
Bob by vicious KO about round 5. Too much fast twitch, way too much firepower. Playing waterbug arm puncher against small targets of limited athleticism does not prepare one for Foster. Quarry-esque KO that has the ringside physician on his toes.
Realistically, Foster is competitive for a while here, but he’s going to retire in his corner with a detached skull, Tunney will jab his head off by the back end of the fight.
Mean Gene. Too much Marine. (USMC > USAF...Now, let's see who rises to the American military rivalry debate...)
Tunney would win. Two technical guys going at it, I'll take the bigger tougher guy with the better record at the higher weights. There's some merit to the argument that Foster is more explosive but in no universe is he more powerful than Dempsey. Barring an early blitz and unexpected success by Foster, I'd imagine that Tunney would grind him out in a technical fight which would lean more his way as the battle went on.