So 2 weeks ago my evo suddenly went fwd. We initially thought the center diff took a ****. Well finally got the tranny pulled and split.. Center diff gears are in tact. Pulled the front diff.. gears are in tact. Pulled "most" of the rear diff/lsd. Everthing looks intact. I have not pulled the lsd out of the rear because I do not understand how to properly reinstall it. I've never "shimmed" a rear end. All the gears in the TC are fine, all gears in the tranny are fine. rear pinion and gears are fine. Drive shaft is fine. I am at a loss trying to find the source of the 90% fwd power ratio.
some pics and video..

 

Well it seems that you have isolated the issue yourself; since you haven't fully inspected the health of the rear LSD, and the rest of the drivetrain looks healthy. Are you 100% sure that all the gear sets in the TC are in good shape?