i was looking at the 40 series si/so on the flowmaster site and it said it fit the 5.4 does anyone know how it works on the 4.6. i have the stock side exit exhaust front of the right rear tire and want to keep it but get better sound (louder n deeper) n keep or gain hp/torque, can i get it by swapin in the 40 series in for the oem on my 97. thanks

 

Yes!!! The Original 40 SI/SO would be a great way to go. I have the same setup with my truck.

The OEM Muffler is bigger than the F/Master, so you will have some pipe mods (very min). If you are going to purchase the muffler yourself, check Summit Racing ($59-69).

I went with the 3in SI/SO, so I had to purchase that size direct from F/Master ($113.00). The OEM pipe size is 2.4 or 2.5, so summit will carry that size for sure.

The 4.6 is not as throaty as the 5.4, but you will still be happy with the exhaust tone. Good luck my friend...

 

why dont the make the 40 series for the 4.6. Because i wanted the 40 but i have to go with the 50 series since they dont make them. The guy at the speed shop says they had back pressure issues that why they are not made for the 4.6.

 

I have the 40 series and it works great. Back pressure issues??
It is loud though, so if you like it loud that is the way to go. If you like it quieter then Magnaflow.

 

thanks yea i thought it might be only for the 5.4 because the 4.6 couldnt build the pressure to keep the torque up, but im gona try and get 1 used
worse case scenario i sell it and try a different one

 

You can put any flowmaster on any car with a pipe expander and a welder

 

Mufflers generally are universal. The 40 series is just recommened for the 5.4, but that didn't stop me from putting it on my 4.6.

 

I have the 40 series on my 4.6 and it runns most excellent but I do have some poor mpg issues but that is to be worked out at the muffler shop this saturday they told me I have my exauhst to short so that is why I get low mpg it is around the 11mpg mark. I am very happy with my flowmaster and that is all I have ever put on my trucks. They told me the same thing about my dodge with the 318 but it runns great too. The only flowmaster I was told not to use by the techs at flowmaster was the 30 series because it is like a straight pipe setup and has no back pressure. I say go with the 40 for sure you will not be disappointed.