Nick,Nick D said:If I had to guess I'd say you got an aluminum one - that's going to be your weight difference. Aluminum is fine, less rotational mass is a good thing for acceleration, but if you really want something beefy just shop for a steel sprocket. I'm sure I've seen them somewhere, if I can find them I'll post a link.
No one in their right mind would even make an Alumunium front sprocket, What he got was just a steel sprocker without and spacers and or cushing added on. JMS, you'll be fine the sprocket will float on the spline within the clearance and help tp align the chain better.