Hagler would win. He got that iron and the better jab. Plus, big height difference but Tarver was really not that rangy. Hagler to out-jab Tarver if Tarver tries to box and out-fight Tarver if Tarver tries to fight.
Tarver is half a foot taller and 30 lbs heavier. Hagler's jab isn't so useful here. How many southpaws did Hagler fight?