Best Muffler mild 318 factory dual exhaust pipes

Hello have 67 formula s notch. looking for best deep sounding muffler that's gonna make me sound a lot faster than I really am. I think the piping is 2.25. the mufflers are off-set on both ends. the muffler case length is about 13 inches. I was looking at the Flowmaster 40's or the Series 44. What other mufflers should I look at. I have Borla on my truck which I like but don't know about putting them on the Barracuda. I guess I'm looking for a deep tone especially when you romp on it. Thanks,Jason