Figured I would do a little write up for anyone past, present, or future and the choice of going with either a 4" downpipe back or a 5". I orignally had a 4" downpipe back into a 7" SoFlo single stack. I have grown out of my stack days and had a guy interested in buying my stack so I decided since I had sold off the bed back part of my exhaust system and was going to buy another full new exhaust to go with the 5". For about the first 8" of the 5" exhaust it stays 3" then into 4" then into the 5" to be able to clear the tranny lines for the added size in exhaust. After that it is very straight forward and fits fairly well but is pretty close to a few different items which is sketchy but perfectly fine. I decided to leave the tailpiece off of my new exhaust and just run it dumped over the axle for a stealth look. Upon start up you can tell a slight bit of noise difference but nothing major. The real difference is when you start pushing on the throttle pedal and you can really hear the deeper tone as well as quite a bit more turbo whistle. Cruising down the hwy at 70 (me being use to my stack) it is very quiet with no droaning and just a real good clean sound. Also it might just be me but from normal cruising speeds both in town and on the hwy I seem to notice a very slight, less then 100 degrees, drop in EGTs. All and all I think I do prefer the 5" over the 4" for the little bit more money it is and the fact that only a handful of people run a 5" so it makes my truck stand slightly apart from the rest :thumb:
Also I do have a 3" downpipe which helps with a slight bit of sound as well as EGTs which may be a slight difference apposed to the stock downpipe. Thanks!
Also I do have a 3" downpipe which helps with a slight bit of sound as well as EGTs which may be a slight difference apposed to the stock downpipe. Thanks!