2017 ram 2500 broken manifold bolts

I've got a 2020 Ram with 5.7 with 62k and took it in last year at 59k for an exhaust leak. I knew there was a leak in front of the muffler but thought it was also one at the driver side manifold. My nephew just had his gaskets replaced so I was nervous about it. They claimed that the manifolds were OK but I still think there was something not quite right there. Now I can really hear it on cold start. I think I'm probably out of luck now being over 60k miles? Not looking forward to having any of the dealers around here working on it, they have proven to be less than competent as well as freaking expensive. When I was under there, it didn't look like fun to get to all the manifold bolts. I wouldn't go with tube headers but wouldn't mind stabbing a different cam in. Saw a story recently on FB with a shop that claimed a 10%+ hp increase with a cam change only.