You will not notice much at all w/ stock turbo. With lots of fuel you will notice a little less egts, that's all. I did all of this, and I don't know if I'd go through the hassle again unless your going for over 500hp.

 

I'm already there, and that's what I want to do. It only makes sense......

 

Yes it makes sense with all your other mods......

 

I have a 03 so. and was considering this mod, but it sounds like it might be a waste for me. Is there any gains to be had in a new muffler? Besides sound that is. I like quite, but would like some performance gain. What is recommended? Currently my calif. so is stock except for a Amsoil drop in air filter and 4" hole in the air box. Eventually I will probably get the xzt modual. This truck is kind of a dog. I want towing power no hot rodding.

 

if you ad any kind of performance module or chip intake and exhaust upgrades will help keep the egt's from getting out of hand. You should still invest in some gauges to monitor your temps. A straight thru muffler will sound pretty good, but likely won't be annoyingly loud. It will help lower egt's and provide better flow.

 

does this 3.5" elbow also apply to the 03 HO trucks?

 

Good question. I know the 04.5 had the larger one, but not sure about the older HO.....someone will know

 

Yes. Almost all 03s had the smaller elbow. There were some, however, that ended up with the 4"in x 4"out elbow somehow..

You probably won't feel anymore power but EGTs should drop by going to the larger elbow.
SOs are a bit doggy in stock form. Throw an XZT on it and you will be very happy with the power increase....

 

the only reason i ask is because when i went to get my truck SP'd at the exhaust shop the guy ask me what year it was. i said 03, then he goes okay its a got a 3.5" to 4" tailpipe. well he fabbed up a pipe and had some else cut the muffler. when he went to put the pipe on it, it didnt fit, the 3.5" end was to small. he then said "huh, its got 4inch". but the exhuast was completely stock with no kitty. thats what got me wondering if there was something different on the 03 HO's like i have! maybe someone replaced it with a exhaust from a newer truck

 

Someone probably replaced it....

 

I wish they just would have done 4 inch to begin with so we wouldn't have all of this confusion!

 

yeah i didnt get why they put a 4" tail pipe and 3.5 from turbo to the tail

very easy to fix 10' section of 4" and i was done no more 3.5"

funny thing i didnt notice any egt difference i was kinda disapointed

 

Well, 1st gens started off with 3" I think!! They have evolved to the 4" stage now. Imagine where they will be 10 years from now. The automakers just worry about making everything work with the stock power. That elbow works fine on a stock truck.

 

FWIW, My SO tows great with the mods listed in the sig. below. Haven't dynoed it, but big difference in power, unloaded and towing. EGTs can exceed 1300° if I'm not careful, keeping one eye on the gauge helps.

 

Your exhaust is stock correct? I guess I am looking for a muffler suggestion. I would like something that is not allot louder than stock, but flows good.