Prime Evander Holyfield was 6′2 208lbs. He was small for a heavyweight in the 90’s and would still be light for a heavyweight in the 70’s. Ali was considered a small heavyweight at 211 lbs. The difference in the golden era (70’s) is that Holyfield would not be outsized by 50 lbs. To demonstrate how Holyfield would do in this era, let's look at the champions of the 70’s.
Joe Frazier. A swarmer with a Philly shell defense and A-frame ( hands at chin with elbows flared out). Depends on bobbing on weaving over lateral movement. Left hook is the big shot.
Holyfield wins this quite handily. Evander Holyfield is an inside fighter who would technically pick apart swarmers by placing hard counters through defensive lapses. Big shot is the headbutt.jk Evander's best weapon is the left uppercut off the break. It's how he began the breakdown of Mike Tyson. The clinch fighting tactics Evander used against Mike Tyson nullified Tyson's left hook and his ability to effectively throw multiple powerful shots. Frazier's ultimate undoing would be the uppercut. Frazier rhythmically would dip his head to avoid punches and his A frame made him susceptible to shots coming from underneath. See Frazier vs Foreman 1 and listen to Howard Cosell.
George Foreman. A power punching infighter who throws everything with murderous intent. No technical setups or traps. Eats a lot of punches to land a few deadly ones. This one is very easy to predict because it happened. Evander Holyfield defeated a 42 year old George Foreman via decision. He would stop young George. Old George didn't have stamina issues like young George. He was never knocked down or out like young George. While slower, old George displayed a multiplicity of punches that were not in his repertoire during his youth( the jab). Holyfield and Foreman would trade fir a few rounds. Foreman would tire because he did not get the usual quick knock out. Then he would be flatlined
Muhammad Ali. A ring tactician who baits opponents into overthrowing power and number of punches in order to land shits. Will concede rounds to reduce an opponents stamina and then land flurries and counters. This is a toss up.
Holyfield would relish at the chance to tee off on someone who is laying on the ropes. However, he is an aggressive counterpuncher. If Ali is doing all baiting and very little throwing, this fight will be uneventful as few punches will land. Both fighters possess granite chins. However, if there is a stoppage, Holyfield would be the victim. In his prime he was stopped by a counter from Riddick Bowe after becoming fatigued. If Ali could get him to throw and then make him pay, Holyfield would get stopped. If Ali can't replicate the demolition job he put together on George Foreman, then Holyfield wins a boring unanimous decision solely due to activity.
Lemon Spinks. A flatfooted undersized brawler with no defensive skills, power, but a ton of courage and workmanship. Lemon would throw punches at Evander just as he did Ali. Only Evander won't back up. Evander would sneak punches in between Leon's endless combos. Then, realizing how much he is landing, Evander would put power into his shots and sleep Leon. Round two or three stoppage.
Ken Norton. A fleet footed chiseled worker. Stick and move. Terrified of punchers. Norton was admitted shy to face big punchers after being erased by George Foreman. Earnie Shavers reinforced this. Norton would move around a lot and win a good share of rounds. Once he gets trapped in the corner, Evander will unleash salvo after salvo until Kenny is comatose. See Norton vs Cooney.
Larry Holmes. The Easton Assassin had the greatest jab of the era. He had a powerful right hand that put down Earnie Shavers, one of the most powerful punchers ever. This was done after Shavers rocked Holmes badly. Holmes out-slicked Kenny Norton to win a world title. This would be the closest fight. And to be honest, the most frustrating as there would be no clear winner. Both men could box and brawl. They could get knocked down and resurrect to do damage. Larry Holmes would land jab after jab and line up the right hand to keep Holyfield at bay. Holyfield would counter and clinch bring the fight to a slow pace. A punch could be the deciding factor of a round. It would come down to who could maintain their preferred range. Larry Holmes would like it outside with long punches. Evander Holyfield would want it up close to deal devastating uppercuts and hooks. Every round starts with fighters at distance so the early parts of each round is where Holmes will be superior. As Holyfield gets the timing of Holmes punches down, he will land his own shots. The problem here is taking damage to get in close. This got Holyfield stopped by Riddick Bowe, after dropping Bowe. This would be a very contentious draw.
In my view, prime Evander Holyfield could be a legend and champion in any era. He could hit, hit with power, take damage, and break guys down.