The exhaust system is 2.5" mentrel bent aluminized tubing, I bought the parts and cut and welded it myself. In the pic above you're looking at 10yr old Flowtech longtubes on my 5.8, they're gone now and the motor got replaced with a 5.0(while I buildup the 5.8), and I have a new set of Flowtech longtubes on that motor. The new headers are totally different and I had to rebuild the whole Y section. What really pissed me off was that these new headers hang lower and come further back and make getting tubing around the tranny crossmember a real bitch, it still hits when I use reverse so I have to make more changes next spring. Needless to say I won't be using Flowtech again, and that's too bad because they're good value for the $$.


The catback on this system is 3" but it's too big for my cammed up 5.0(low rpm TQ is weak), so that's why I suggest using 2.5" on that motor. I had a complete MAC system on my previous truck that was 2.5" all the way and it had much better TQ off idle. On this system I originally had the muffler(Flowmaster Super44) at the rear axle but the noise in the cab was unbearable so I moved it up behind the cat and that completely eliminated the droning inside. I have since tried a 50 series and it really isn't much quieter so I'm going to try a Magnaflow next, the Flowmasters crackle and bark a bit too much for my liking I'd rather have a muted rumble. Here's a pic of the new muffler location..