Exhaust Question

matt04 · July 17, 2007

I have a 2004 Silverado z71 with the 5.3. I'm getting ready to swap out the muffler on it and replace it with the new super 44 from flowmaster. Does anyone know what sizes pipe is on these trucks stock before i crawl under there and measure myself?

crepitus · July 18, 2007

i just did this last weekend. i ended up getting a magnaflow 12589 3" in 3" out. the pipes on our struck are 2.75 od so you have to make up some reducers or have a shop install it. i like the muffler. its loud when taking off but when just crusing you dont hear anything. only think i dont like is the slight vibration in the floor when you are on it. might try putting the stock heat shield on to see if it helps.

leboyd · July 18, 2007

i just did this last weekend. i ended up getting a magnaflow 12589 3" in 3" out. the pipes on our struck are 2.75 od so you have to make up some reducers or have a shop install it. i like the muffler. its loud when taking off but when just crusing you dont hear anything. only think i dont like is the slight vibration in the floor when you are on it. might try putting the stock heat shield on to see if it helps.

Did the heat shield work?

matt04 · July 19, 2007

I measured the pipe and your right its 2.75 which i thought was weird. i didnt know whther to go with a 3" or 2.5" muffler. I'm sticking with the super 44. I've heard them on a few different cars and i think they'd sound good on the truck. Had an SLP loudmouth on my camaro and loved it. I like my exhaust noticeable.