i have a 4.2l and tow a boat often. i know i want a flowmaster but which one do i get, 40 series, 50 series or 70 series. I want it to have a good sound outside and be herd when im comming around the corner but not be crazy loud inside or crazy when towing. Which one do i get??

 

50 DF SI/DO with echo chambers (tips).

 

If you tow with a V6 than torque should be important to you. If you have decided to go with a Flowmaster, I would suggest a single in/single out muffler. Dual out may sound better but you would probably loose torque and couldn't run them straight out the rear with out getting exhaust all over the boat and I'm sure you wouldn't want that. I just installed a Magnaflow on my Screw. Love it but it is pretty quiet however I gained HP and torque. The more I drive it the more power it seems to have. I did not reset the computer but it seems like a different truck. In the Flowmaster line, I would suggest the 50 to help keep the resonance down a little. JMO though.

 

A dual exhaust will not make you lose torque contrary to popular belief. A good dual exhaust will 9 times out of 10 give you an increase in torque but duals will also more your torque band slightly higher, but you won't lose torque by any means.

 

wytlightning,
I see what you are saying but I have to make a point, if you flow too much you will in fact move your torque band higher in the rpm range, doing this will make your truck shift more on hills and when towing, this is what most people don't want at all. I have not installed duals on my truck yet because of this. However if I ever do it will be a magnaflow because I have heard of a lot of people here on the forum that have them and they seem to gain some low end.

 

I see what your saying and I agree with you on the modular V8 engine because they carry all there torque down low. On the other hand the Pushrod V6 actually has a wide torque band. I think I agree with you though on the towing part and agree that a single exhaust would be better suited to towing.