If I buy a muffler (just the muffler, not a catback or axleback), what inlet diameter do I need? I am planning to just take it to a mom & pop's muffler shop and have it installed. What is the stock piping? Is it 2.25"? Can I tell them to use 2.5 and make an axle back? If I can use 2.5, what size of muffler do i need then? Sorry.. im a noob.