3.0 case G50 gearbox, issues

[ONQRACIng]

I just installed a new ring gear on my 2.9/G50 engine. The new gear was from our host, and is the one with the extended/offset teeth for better pinon engagement.

Here is the issue. The starter energizes, I see it move from engagement, but the engine will not spin. The clearance from edge of the ring gear to the gearbox case is VERY tight. Is there a spec for this clearance, and better yet, can it be jammed?

THe new gear is the same OD as the old, which was ok., or can it be a starter issue? I need to spin it off the engine to check pinion..

Any thoughts would be great..