Thinking of exhaust mod

I have a pypes system with the x-pipe . Right now it's hooked up to the stock 175K mile 318 with a set of flowtech headers . I like the way this system works at idle and just cruising around it's pretty mellow but give it some gas and it has a raspy snarl ! It never seems loud but I sure notice how quiet it seems after I shut The car off . Will be interesting to see how it sounds after I drop the new 360 in !