I want to replace my stock exhaust. I don't want this mod to get up to $300 - my question is..
Is just replacing the stock muffler with a flow or gib enough? Or do I have to replace the entire system?

 

I went the muffler only route. Is a full cat back with mandrel bent tailpipes better.....probably....maybe. But IMO you will not feel the difference on a stock or only slightly modded engine. Also the shop told me that a mandrel bent system tailpipe will not last as long since it is stretched from the inside and actually thins the pipe. I don't know if that is accurate or not, I really don't think one will last longer than the other. My fear was that going with a gibson would be to quite so I opted for a glasspak from a muffler shop. It cost $60 installed, is aluminized and sounds absolutely awesome with the stock tail pipes. You can make it quite with light throttle or push the pedal a little harder and definately here the exhaust. At highway speeds i get "0" resonance and it is as quite as stock til you load the engine to pull a hill or something. You can go with a FM, Gibson, Magnaflow but will spend about $125 installed. Good Luck

 

A muffler only is a great improvement due to the fact that a HP muffler flows about twice as much as the factory one. You can also choose your sound (or attitude ).

 

I have a 2001 F150 4.6L. I have tried everything to get my truck to perform with an exhaust. I tried flowmaster, glasspacks and a spintech. All of them made my truck loose all of its bottom end torque. I tow a boat so I can't have this. I called gibson and they said it is because the new ford motors need backpressure for low end torque. So I took their word for it and bought the single 3" swept side, because they said it had the correct amount of back pressure. They were right! I took my truck to my buddys shop that had a dyno and it made 12 horsepower and 19 ft/lbs of torque to the rear wheels. I was amazed. The weird part is that it is not loud and annoynig like the other ones. Does anyone know of any 2wd lift kits?