Are the flanges and holes on a 7-1/4 any different than the ones on an 8-3/4?

I had a shop that builds custom rear ends redrilll my small bolt 8-3/4 axles to large bolt and thread them to install 1/2 inch thread in studs.
He installed new axle bearings at the same time.

They would install press in (knurled) 7/16th studs (GM I believe) but said the outside diameter of the Mopar 1/2 inch studs was to large but said thread in 1/2 inch studs would be fine.