you cant really go to big with a diesel. with that being said anything over 4in is just a waist unless you are going to be over 500 horsepower. 5in wont hurt but it is more of a bling thing. 4 will flow all the air that you need
I have a 5" on mine and the main reason I got it was because when I was looking to buy exhaust I found this listed on ebay for way cheaper than all the rest of the 4" kits at the time. It's listed as a "flo pro" or something like that on there. I like it has a good diesel sound, and it makes my friend with an 05 hates riding in my truck because it makes him want to spend money.
No advanatge till you see 500 RWHP, then you'll see a small EGT bebefit. On a LB7 be prepared for louder than a 4 incher too, the late model LLY/LBZ have a different engine set up and are quite a bit less prone to drone and loudness than the LB7's are. If you have any questions just call us we stock all the MBRP and will be glad to help you.
I would like to see numbers on a flow comparison after 500 hp to backup this statement. Has anyone actually ever done this test?
dirtshredder- Since you have an 02 LB7, be prepared for a VERY big change in exhaust tone when you switch to a 4" or 5" kit. The 5" kit will sound a little deeper and more aggressive however. A 4" kit will give you all the flow/hp you need, but the 5" does have cool factor. If you want it very aggressive sounding, get the 5". If you want a nice low rumble, get the 4". If you have any questions, feel free to give us a call.
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