I have looked all over but I cannot find the spec that says how much slack the chain should have when the bike is on the center stand. Can you help me out here??

where did you look ?! The chain slack is mentioned in all manuals but with the wheels on the floor and some weight on the back. (hence when drive shaft, swingarm axle and rear axle are in one line as that`s the point when the chain is streched the most)

G.