What part number did you use? single in dual out right?I just installed the 18" Magnaflow only (no Y ) at my friends gas station. I helped with his son, took us about 25 mins and I gave him $40. Really need to put the truck on the lift, makes it a lot easier! You are going to LOVE the difference and the SOUND.... Sooo glad I did that mod and glad I got the 18" not the 14 or the 22....Good luck!