Well I need to weld in a bung for my WB that is coming soon, so I figured I would redo the rest of my exhaust. Currently have dual 2.5 pipes going into a dual in/dual out magnaflow dumped after the muffler. I did this before I researched, , needless to say it pretty much killed my bottom end, IMO way to much for a stock 4.8....

So the new plan is to put a Magnaflow Y after the cats and use a single in/out magnaflow. My truck is pretty much stock and I will probably add headers and maybe a baby cam down the road so the question is 2.5 or 3 inch for the mid-pipe and muffler. I have my own welder and so welding it together is no big deal. I understand that the stock size is ~2.75 so the options are:

1. 2.5 pipe into a 2.5 single in/out dumped over the axle
2. 3.0 pipe into a 2.5 single in/out dumped over the axle
3. 2.5 pipe into a 3 single in/out dumped over the axle
4. 3.0 pipe into a 3 single in/out dumped over the axle

Thanks in advance....

 

I vote number 3.

 

#3 is what I did on mine--with pretty much the same eventually will do ideas.

 

#4 IMO

 

Thanks for the replies and opinions. Well this is what I decided on:

Magnaflow Y - 2.5in into 3in
then
2.5 midpipe (both ends enlarged to 3in)
then
Magnaflow 3in single in/out
then
Factory tailpipe cut to dump over axle.

Sound good. This what when and if I upgrade in the future I can swap out the 2.5 midpipe to a 3in easily... From what I have read this setup should bring back some of my Low end loss, it may suffer up top a little, but hey it is a stock 4.8....

 

I'd go with #4, or you could just get a stock d-max setup and fab up the connection to your truck. That's what I did with mine.

 

Well, I pretty much got everything figured out except the size of the mid pipe, maybe I will just with the 3 in mid pipe.... I have never seen the dmax setup, so I don't know about it, I really like fabbing up my own stuff, when I was in college I worked in an exhaust shop and I really enjoy fabbing up my own stuff. Actually this will be the 3rd time I have changed my exhaust...

 

The stock d-max exhaust will pretty much hang right in there, but you will have to do a little fabbing to make it work. Even with the stock d-max muffler it has a great clean sound, nothing too loud.

 

Id do #4

 

IMO i would go w/ No.4...wouldn't u lose back pressure w/ No.3?