When I had my engine apart, I had the center bolt out, as well as the surrounding ones. It had the washers stacked there, but I don't remember off the top of my head if they would have held everything together without the surrounding bolts, or if they would have allowed the pulley and harmonic ballancer to come off.

If you do pull the center bolt, make sure you have the ability to reinstall it.
It required torquing to ~230 ft/lbs. With my engine on a stand, and locked on the rear, I was still hard pressed to reach the rated torque, with a 3' long 1/2" drive torque wrench!

If you can wait until after this weekend, I'll let you know how mine goes back together, though. I'm about to tear into the water pump myself. (Seemingly the only part I didn't change! )

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-Josh
Testing the cheap Mercedes axiom, one bolt at a time...