When I see a g54b not running I think head gasket when I see a 3.0 not running I think computer now. I did the stud kit and laminate head gasket on my last build never had any issues until it burnt up in a fire a couple years later. One thing with the studs is to clean the block bolt holes out to get the studs in correctly or the back valve cover can hang up on the breather shield if it’s not fully in place causing the valve cover to not seal correctly.