okay guys, I've got a couple of questions for you about installing a flowmaster on my 04 F-150 4.6l STX.

I've got a brand new Flowmaster Delta 40 with 2.5" inlet and outlet SI/SO that I've had setting around for a while. The muffler is offset in and offset out if it helps its flowmaster P/N 942543.

My question is, will this 2.5" size flowmaster work on my truck? I was not able to find the size of exhaust pipe my STX has (and didn't have time to put some calipers on it to measure)

Secondly, is the offset in and out going to matter during installation? or do in need a centered inlet or does it even really matter?

I just wanted to check with you guys because in the past with all my Mustangs and other trucks I've just driven to the exhaust shope and said I wanted a Flowmaster 40 series and they always grabbed what they needed off the shelf and installed them. Like I said, I've had this muffler for a while and though i would use it if possible. If I need a different one I'll get it, but why waste more money if I dont have too you know.

One last question, how does the 4.6l sound with a SI/SO flowmaster 40 series? I'm thinking about turning it down because later i may run it off to the side depending if i get the Roush valance and side skirts.

sorry for all the questions, just wanting to see if what I have is usefull.

thanks in advance,
Josh

 

I am not too sure on the pipe diameter on a 4.6 truck. I would assume it would be 2.5 like the 5.4s but either way a good muffler shop should be able to make it work. A friend of mine has a SI/SO 40 series with a 3.5" tip. You can hear it pretty good in the cab but he likes it loud. If you wanted it quieter run a tail pipe without a tip or for louder use a turndown