What is an easy way to make my truck sound like it has "flowmaster" straight pipes without paying for the upgr?

I have an f150 and I want it to have that deep "muscle car" sound|||Drill a few small holes on the surface of the muffler.|||get a old school glass pack muffler and you will want to heat that up then cool it to break up the glass and it will give you a great sound with keeping emissions