I am leaning towards a prime Jimmy Young over a prime Jerry Quarry. Quarry always seemed to have problems with the sleek quick fighters like Eddie Machen, Jimmy Ellis, Muhammad Ali. Quarry did well against ponderous sluggers like Ron Lyle, Earnie Shavers, Mac Foster. I think that Young sticks with his jab, flurries on the inside, ties up Quarry when necessary and wins the decision. Grebfan9 www.firstroundboxing.com
All of those losses, however, happened before and after Jimmy was in his prime. During his prime -- 1975 to 1977 -- Young's only losses were questionable decisions to Ali and Norton.
I remember a veteran promoter (name escapes me) saying "Quarry wouldn't want any part of this guy" after watching Young dismantle Lyle. Unless Quarry could land flush early in a round (and maybe not even then) Young has his way with his boxing skills, counterpunching, and side to side almost quasi-Walcott-ish technique (another guy all wrong for Jerry IMO) Also consider that, when two accomplished counter-punchers engage each other, often the fight can lapse into "snooze-ville"... my $0.02