Razor Ruddock, Bonecrusher Smith, Pinklon Thomas and Mitch Green are some of the contenders of the 80's that I feel would beat Klitschko.
He would do nealry as good as Tyson but would lose one or two fights due to his weaknesses. He would be the best between the Holmes and the Lewis era though.
Mitch Blood Green vs. Wlad would be interesting. Green had a great beard and he certainly wouldn't be intimidated by Wlad. He'd be laughing at Wladimir the entire time and may be able to get in his head.
He'd suffer some losses just like he did right now. I think he'd have a few good years of dominant performances like he has now though. If there's one thing he has over them then it's dedication, living a clean life and consistency. If he starts in, say, the early 80's, loses a couple there (i can see Cobb doing what Purrity did... walk him down, take a shitload of punishement and stop him late) ... and reach his peak in '86, i think he could beat the same opponents Tyson beat. I think Bruno might give him most trouble actually, who has the power to knock him out and an excellent jab. I think Williams would be stopped by a left hook sooner or later, Tubbs would be game but ultimately not end up winning, Thomas is a hard one, but the Thomas Tyson faced wasn't the best version of him and i'd pick Wlad over him in 87. Smith would probably be a safe victory and a boring fight, unless Smith lands something big. Dito for Berbick. Biggs and Spinks would be easy victories.
Witherspoon Thomas Tubbs holmes spinx tucker williams ruddock bonecrusher berbick bruno page???? hed be in for the ride of his life