I Just bought an 07 1500hd classic, I forgot how quiet a stock truck is after driving my old truck for so long. I would like it to be a little louder without the drone of course. Which muffler is better the magna flow 12590 or the 12398? They are both 3 inch di/so so the only difference will be the sound because of the case size and material. I am only going to replace the muffler not the cat back route this time to cut costs. Are these two my best options or is there something better out there that I don't know about. Thanks

 

Might give these a look too.
FLO~PRO - BIG Oval 12x9

 

I think if I did that I might want to find the tail pipes from a 2500 and run the di/do because it states that it flows more. Anyone have any experience with doing that?

 

After looking at several trucks and trying to decide on what I could use from a different stock truck I am even more confused. I thought the 2500hd's had a dual out exhaust but is that only y'd back into a single exhuast? If that is the case then would it not just make as much sense to go with a single out muffler and and find a 2500hd exhaust to go bigger?

 

Go open Y pipe like me
not all that loud at idle but screams at WOT

 

No y pipe on the 6.0, and my wife would not be very happy. after reading around I would like to do a true dual in and out with the flo pro muffler since i haven't read anywhere that they drone. The replacement muffler I think would be too quiet but I think the di\do would be perfect. I need to find somebody locally that can bend 3" and just try that, maybe.......

 

if you wanna do true duals, why would you get a di/do muffler? you need to use an x or h pipe going into 2 si/so mufflers to do it right.

 

I haven't found anywhere that it is necessary to flow any more, I am not opposed just cheap. I was looking at nice x pipes to go in front of the muffler and will probably do that at the same time as the muffler swap. From a muffler cost standpoint 1 is cheaper than 2 but I am open to 2 if they sound better and flow more, eventually the truck will have some type of FI and If I set up my exhaust now it would save time and money at that point. I don't think I will ever push it so that I need more flow than a di/do muffler, but I am ignorant about the benefits of splitting the muffler. Someone please educate the ignorant. I am wanting a little more sound without any drone and to keep my wife happy with the sound tia

 

I would use the magnaflow dual 3" inlet, single 4" outlet

 

The magnaflows DI/DO have a built in x-pipe.. I would not recommend the magnaflow, I hate the way mine sounds. I've tried it both ways single tail & dual tails. Dual mufflers with H-pipe will be the next thing I try.