I doubt it, and it's not necessarily the thickness, but the balance position and amount on the balancer that matters.
On the second question I know 318 and 360 pulleys can be mounted on the magnum damper, so I would think the 273 would also.
One bolt hole on the pulley doesn't quite line up and needs to be egged out just a little for all the bolts to go in.
I'm running the stock pulleys from my old 318 on my magnum right now.
