If those Power Tips you got are aluminium, they may melt over time and cause you problems.
You'll want to get steel muffler insert with closed centre. This will force exhaust to flow through packing material and it will dampen noise quite a bit. Also improves your mid-range power on pre-gen quite nicely as well.
https://www.amazon.com/dp/B075HCVJTM
https://www.amazon.com/dp/B017YJ7TMQ
https://www.amazon.com/dp/B07WYNV38S
https://www.amazon.com/dp/B07FF1TCW6
There's quite a few designs out there. Measure your muffler's outlet and find one that fits.