Hello all, I have really gotten alot out of the info everyone has posted here. I've got a 01 ECRB 1500 Z71 that I picked up used with 71,000 on it. As of tonight I have changed the plugs (just went stock), plug wires (a little better than stock) took care of the coolant to the throttle body and debating on putting the screen back in the MAF
The previous owner had left the stock exhaust on it and Yd' off the stock muffler for the dual look. I want to do a true dual from the cats back but unsure of what size pipe ( I was thinking 2-1/2) and flowmaster 50 series. Now I was wondering what comes with the install of either a X or and H. Can anyone give some advice? Don't want to go too big or too loud I still put the family in it on occasion

 

x pipe on the exhaust. you will lose some low end when you go to true dual. yes the screen back in will help you.

 

With the 5.3 should I leave it at a 2 1/2"? A guy at work said to go with a 3" but I think that it is too big. I am going to keep it mostly stock. I want to add electric fans and maybe a spacer for the t-body and that is right about where I want it. It has 4.11s' in it so the little bit I miss on the bottom end won't be missed too much but I want to pick up on the gas mileage some since I travel in it alot

 

2 1/2 is plenty big.

 

2.5" duals are still too big for a 5.3. 3" is WAY too big for duals on a N/A application. I'd just stick to the single in, dual out muffler it'll save money and keep a lot of bottom end power. 02Denali went back to a Y-pipe setup from true duals...

Mangaflow muffers and Dynomax actually make some power where as Flowmaster make a lot of sound. The SuperTurbo from Dynomax is a great muffler at WOT and very, very tame a cruising speeds. That's what I had on my old '99 Z71.

TB spacers are junk, ask Kevin (v8 is his name on here)...I think he dyno'd a power loss with one.

E-fans are a great choice. Most of us use the LS1 fans as they are cheap and work great.

A custom tune will help a LOT with power and some fuel economy if you can keep your foot out of it.

 

I a running a SS Silverado exhaust on my 5.3. Noticable performance and just a bit louder than stock. I had them run true duals into the muffler and it has a big single outlet.

 

dont get chokemaster they suck!

 

i went with flowmaster delta 40's. great sound - check out the clip in my sig. i also added a x pipe, ordered it off the internet somewhere. didn't really lose any off the bottom, maybe a little but the custom tune brought most of it back...

 

Flowmaster is a great sounding muffler but I actually felt like I had more power with my stock exhaust. I cut the muffler off lost some bottom end but top end roll's! I am wantingto get something better than flows though. The interior resonance was louder with the flow than with nothing. I was just tired of that ******' drone!

 

I'd like to thank everyone for their thoughts . I called a couple exhaust shops today to get some prices and the one convinced me to go with a Dynomax single in dual out muffller, but sticking with the 2.5.
I am going to put the screen back in tonight after I fill up. Right now I am getting 20 miles to the gallon, so I want to see how it effects mileage. I am just getting out of a Grand Prix that I had descreened and drove it for 4 years with no problems and got great mileage and power. After looking at the plugs last night they seemed to be burning a little rich but nothing bad.
Now with the electric fans where is everyone getting them? Hooking them up shouldn't be a problem but should I go to one of the local part stores and get the fans? They might be this weekends project and then maybe working on the air intake for some better flow. Once again thanks