2008 RCSB 5.3/4l60e, 100% stock except for a Radix 112HH. I purchased a 3.1" pulley, HPTuners, PLX wideband, and Pacesetter LT's and midpipe. The PS midpipe y's into a single 3", is this going to be large enough? If it's too restrictive, I would just ditch the mid-pipes and have something custom done.

I haven't picked up a muffler yet, but was thinking one (or two?) of the large can magnaflows.

 

3 in is plenty large enough with these trucks a little restriction is good to keep the low end tourque some trucks out there are running 2 1/2 in but since you have a Radix you'll be fine

 

IMO if you want a little bit more flow, chop off all the pipe right after the y-connection, then use 3.5" pipe and a 3.5" muffler. It is alot cheaper that doing duals... Just my .02....

 

Thanks for the responses.

Will going to a larger pipe size after the merge gain me anything, or just not cause anymore restrictions? One thing I am a bit worried about is getting drone in the cab (this is my DD), and thought that the larger pipe diameter might contribute to drone.