ok was wondering what kind of difference there is between weld in flowmaster 40 or delta 40 cannot remember wich ones they are that i have and getting a true flowmaster american thunder catback or mac catback....i have the mac prochamber and like the sound so not really wanting to change to much...just the difference i guess thanx...mike

 

The CB has larger pipe that will help it flow better.

 

delta anything flowmaster is the quieter version of that muffler. Get the mac catback they are cheap and flow better then flows and in my opinon sound better.