2.4l LE5 Throttle Body Actual Size...

2008 LE5 2.4l crate engine installed in a 2009 HHR. Starts and runs. Preparing for tune this week. Engine came with intake manifold but not the throttle body. Used one from a 2.2l and it runs but before I waste my time tuning, I need to know if this is the right one. The internal bore (down where the butterfly valve is) looks like around 56 'ish mm. Another 2.4l that I have access to is around 65 'ish mm down in the bore.
Engine is naturally aspirated and throttle body is 6 pin. The one I compared it to is a 2006 hhr and it's an 8 pin. What I'm looking for is to know exactly which throttle body I need... and a part number would be helpful if anyone happens to have one laying around. Anyone have any first hand info on this?