My Opinion
Phil Heath, nobody has a better back double bicep, back lat spread, side chest and side tricep.
If Kai comes in shredded and deathly dry showing all his muscle maturity then Kai wins side poses and front lat spread.
It will be between Dexter and Rhoden for the abs and thigh, front double bicep. Of course if Wolf is on (which doesn't seem possible at this point).
I really dont see how Kevin will compare favourably with the current era. We have a romanticised view of the 90s because of the magazines etc. I wouldnt be surprised if the judging is spot on and they bring it that Compton and McCarver place ahead of Levrone.