Quick question before I take a drill/grinder to the flex plate, I've got a 2000 C5 LS1 engine for a street rod project but it's got an adapter riveted to the flex plate for the torque tube attachment. I need to drill that off before I mate a transmission yeah? it had 3 bolts I removed but then I realized the other 3 were rivets, hadn't seen that before.

 

Why not just get a normal flexplate?