It was flat. I checked everywhere before mounting.
It sit flush just fine all the way down and the two halves where touching everywhere that I could see. Crank spun freely. Then when I began to torque down literally the first bolt it just cracked like in the photo.
I did things no different than I have with any other vespa case in the past and I would say this one was actually going very well before this. The bearings were fully seated everywhere which usually isn't the case. I often have to fight them.
So I guess this is on hold until I get a new one in from Moparts. On the bright side I'll have to upgrade to a 19mm dellorto carb for that side. So maybe I'll see a performance gain compared to the theoretical setup that was gonna use the 13mm SHA for that side carb.