I removed my Super 44 series Flowmasters and went BBK high flow catted x pipe and strait pipes out the back. It sounds like this exhaust clip. [video]https://youtu.be/Vcb13hTwzrk[/video] It sounds good but it feels like I lost bottom end power but gained top end power. I just have a stock 114k mile 5.0l engine no cam or anything. Also will it harm the engine with the loss of back pressure? I'm having a hard time restraining myself from driving around without hard accelerations. With the Flowmasters the car felt like it didn't like to rev higher then 3k rpm. Now it just revs up so much smoother and easier but I'm driving it harder because of it now.