i love my 5" straight pipe it sounds amazing!

 

I personally love my 4 in Straight pipe with the silver 64!!! It has a wicked whistle to it

 

I'll leave the whistle to the 6.0's... the most popular comment i get is '' no dude really i thought it was a bad *** semi coming'' 5'' into a 7'' by almost 4' tip right out the back from the factory style... got a lot of cummins around here but its nice to know everyone knows its me comin..

 

Ok, so after doing some research I've found a diamond eye 4" for $240 free shipping or $330 free shipping for 5".

But I'm torn between which one to get! I like truck sound but it's the going down the highway droning away which gets to me...

Just for ***** and giggles I took a ruler to my exhaust and it measures out at about 2.5"? Does this sound right? That's after the muffler...

Now I'm wondering if 4" is enough...

 

4" is more than enough but the 5" will give you a little deeper tone.

 

im pretty sure luke has a 5in system for under 300