Young was supposedly beat up against Shavers until Shavers slowened down in the mid/late rounds which allowed Young back into the fight and probably should have gotten him the decision. Frazier wouldn't run out of gas.
I think Frazier would take him by a decision, I think Jimmy was slick enough to stay alive for the entire night, but he would be glad it was over.
Young did outbox Ron Lyle only three months afterwards. These were his notable performances around that time until fighting Ali in 1976.
Frazier was fading badly at this time. Although he matches up well with Young prime-for-prime, i'd pick Young at this point in not an easy fight.
I don't see Young opening up enough against Frazier's onslaught (even a faded Frazier), or having the power to get his respect. Frazier by clear decision.
I think Fraziers pressure and bodywork is all wrong for Youngs slippery running game that worked well against Foreman/Ali
Lyle would've been considered old even at the time he took up boxing. Despite being 35 that was probably the peak of his boxing career. Impressive win for Young but Lyle is no Joe Frazier. He did well against slow sluggers with stamina problems but Frazier would put the pressure on him.
Frazier UD. The fight would be good for Young early but he would be overwhelmed late and lose a decision. Joe still had a drop left in the tank in 1975. He would have enough to beat Young as he matches up well with him.