I'm looking for the best exhaust set up for my 95 4.9. I live in MN where we don't have vehicle emissions tests so I'd like to go no cats. My exhaust knowledge is pretty low so making a combination of what I've heard personally and what people have told me to do, the set up I am thinking right now is:
True duals with flowmaster 40s to 45 degree right behind the rear wheels. No cats, 2.25" or 2.5" pipe. Does this sound like a good plan or no? Thanks

 

Header or factory manifold? Unless the catalytic converter is clogged and/or coming apart, you are really not going to gain anything by removing it. Have you heard the I6 'split up' into a dual exhaust? I think it would sound terrible and might actually lose some low end torque in the process. If it was mine and it needed a new cat I would replace it with a performance (high flow) and run a single 2 1/2" system. If you want to run a dual outlet muffler

 

There is "Zero" reason to run the truck without a catalytic converter.

Also true duals are a waste of money.

The I6 will never sound like a V8 or any other V6 on the road.

Keep the piping 2.25-2.5. I dumped my exhaust right out in front of the passenger rear tire. My
You can also search for Lew52 here on FTE. He did a lot of exhaust work to his and sounded nice on the I6.

 

There are two main styles of aftermarket "loud" mufflers out there: Chambered, and flow-through.

Baffled mufflers are things like Flowmasters. They give that characteristic "tinny" or metallic rattling sound, which some people really like. As it's the classic "muscle car" sound. I personally think it sounds terrible - especially on 6 and 4 cylinder engines.

Flow through mufflers are things like Magnaflow mufflers. They have a straight-through perforated tube through a large chamber packed with sound absorbing materials, fiberglass matting is pretty common. These give a "smoother" tone. To me, these sound better in generally - especially on 4 and 6 cylinder engines. The classic cherry bomb/thrust "glasspack" style mufflers fall into this category as well, but they don't really have enough sound absorbing material to quiet the exhaust down.

True dual exhaust can be done with the 4.9 thanks to the dual manifolds it has, but it will likely sound terrible unless you put in an H-pipe or X-pipe between the two manifolds. True dual exhaust will also offer no real performance benefit to the 4.9. Your best bet is to do a 2-1-2 design. Have the two manifold pipes converge into one muffler, and then split it back out into two at the rear of the truck.

 

Huh I had always been told that the magnaflows on the I6 would make it sound like a Subaru with a fart can once on the highway.

Also I do think my stock cat is clogged and new hi flow cats are expensive so I would like to go just pipe and muffler, as stated in the original post we don't have any emissions testing so what's he big deal? Thanks for the help

 

Not sure who told you that, because it really isn't true.

But you do need to keep in mind that the 4.9 is never going to have a deep throaty V8 sound. It's always going to sound a little high-strung - it's just how 6-cylinder engines sound.

 

So what magnaflow muffler would be best for the 4.9?

 

That, I couldn't tell you. Like I said, some people like the sound of flowmasters, some people like the sound of magnaflow.

 

Ok thanks, just by watching a few videos I think I like the magnaflow a bit better but to me both sound good. do you know which will add more torque and power?

 

The mangaflows's straight through design flows a bit better. But neither muffler will add a noticeable amount of power to a 4.9. The 4.9's power is not being held up by the exhaust in the slightest.

 

Ah I see, thanks for your help