IMO, Loose TC bolts can also damage the threads of the bosses and degrade retention. New bolts, clean threads of all oil, Loctite and torque. Wait for the Loctite to setup after your install.
Also, I had leaking valve covers. Finally noticed the threads on the valve cover bolts were about gone!
If a bolt comes lose, most likely the installer messed up somehow.
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.
1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"