Is there a difference between a 5.4 catback and a 4.6?

 

From what I've heard should be the same exhaust for either motor

 

Good to know. The headers are different right? Would headers from a 99-04 mustang 2v fit a 4.6?

 

they should bolt right up to the motor... the question is will they fit with everything else in ur engine bay

 

they may bolt to the motor, but there is question to whether or not they will bolt up to the rest of the exhaust piping and if the EGR tube is in the exact same place.
And if you look on the magnaflow website, their systems are listed as:

F-150 Light Duty,
4.6L/5.4L V-8, SC/SB,
rear side exit, 5"x8"x18" p-SS muffler,
3" SS tubing, 4" slash/p-SS tip ****June 2004-up manufacture dates

so yeah, they are the same.

 

BlueScrew4.6,

Do you have HP/TQ numbers before? 216RWHP & 265RWTQ seem kinda low IMO. On my 4.6 my baseline on 87 octane was 200RWHP & 240RWTQ STOCK. And i have seem easy 30-40+RWTQ on the 4.6 after a tune + intake alone. Just wondering what octane considering what you have done seems low numbers.

 

Keep in mind this was just (literally 1st run) after I re-loaded the 93 octane performance tune. So the adaptive strategy hadn't kicked in by this point. Also, the UD pullies weren't installed when it was put up on the dyno. I need desperately to load this thing back up on a dyno and get a fresh set of numbers. Should be better by now, as I haven't had to re-load the tune in quite some time so there has been plenty of drive cycles since then. I'm awaiting the announcement of the next Troyer Dyno Day so maybe the man himself can take a look at this thing and see whats up.

 

Are headers the same too?