I just bought an 07 Silverado with a flowmaster on it. Wanting to replace with a stock muffler. Called Rusty muffler and he said he had multiple ones he could install that he cut off brand new trucks. Are there any issues to think about in terms of installing, say, a 2016 Silverado OEM muffler on a 2007? Things like backpressure differences that could cause problems and such? Would it be better to just purchase something that is listed for that year model truck on Rock Auto and just have it installed? Thanks in advance.