K-Frame bolts Help

Woking on my 70 Barracuda. Going trough all the bolts to retorque after putting 500 miles on her, Has anyone modified the K frame bolts? I cannot tighten the front two to 145 foot pounds as it seems the nuts inside the frame rail are turning, Almost feels like the bolt is ready to snap but I am sure it is the nut breaking loose inside the frame rail. I am afraid to torque any more as it could snap something,

Any suggestions?
Author: SFEbody