If you bolt them in with any torque on the nuts, you WILL collapse the frame section. Seen that many times. Bolted in frame connecters are absolute junk and serve no purpose. Sorry, but that's a fact. If they're welded in correctly, nothing is going to tear. On that note, it's a really good idea to gusset the butt welds where the connector butts up against the trans x-member.

For the bolt-in fans, I have some MP bolt-ins for sale. $50 for both.