I think you should be able to use 3" cats. The HD's have larger pipe from the manifolds back. The 2.5" ones will probably still work fine if you already got them.

 

I have the FloPro HD (diso) muffler on my truck. It is only slightly louder than stock and has a mellow growl at wot. I can hardly hear it on the highway with the 3.73 gears. I paid about $150 installed and picked up 8 rwhp and 28rwtq. I have had the 70 series Flowmasters and a couple of Hooker mufflers and there is no comparison. I am quite happy I went with the FloPro. If you want it louder they offer a dual-out muffler.

 

What size is the stock intermediate pipe? Or pipes?

I just bought a 2005 1/2 ton w/ a 5.3 last week . I used to have proflo twisters on my Z28. 'Course, they were w/ 3inch true duals. But the sound was frickin awesome.

TIA.. I'll post more questions later - in a whole thread of my own.



Shawn

 

aaaaaahhhhhhhhh!!!!!!!!! still can't decide. has anyone put a magnaflow on a cc before? it's such a good price at $370 but i can't handle resonance. my baby will be sitting right above the muffler in the back seat. wifey would kill me if it was too loud. there are no muffler shops around here. 3" cats should be here in a few days. i need to make a decision asap.


Flopro 2503 or magnaflow catback or custom true dual with x pipe

should i do the x pipe regardless?

notice how i listed the options by lowest price first, lol

 

i just ordered a flopro 3" X pipe and flopro 2503 muffler from completeexhaust. $205 shipped. Now I just have to wait for them and the cats to get here and find someone who can/will weld it all in place for me. Should i have it all welded or just use clamps and do it myself?

 

I would have it welded up.

 

had the dynatech cats, flopro x pipe and flopro 2503 all welded on today. took the shop 5hrs. wtf? $350 later, it sounds cool. nice rumble. i think most of the noise is coming from the cats though. the muffler sounds pretty quiet. it turns out my cats were fine, not fried like steve at whipple guaranteed me they would be. what a ********.

 

The OE HD cats are badass cats.Take a pic of them and post them up in the F/S section. 5Hrs? WTF My flopro was $175 installed using a mandrel bend going out and flanged in the front.Your truck should sound great and no drone.

 

your 2500HD should have mandrel bent 3" tubes all the way back. you can save some cheese and get the flo pro that will weld right in place.

 

A day late and a $ short ?!?!?!