Ok, I have a 97 F-150 4.2 5 speed with 272,000 miles on it. Got a rebuilt engine with 20,000 miles always run with Mobile 1 synthetic and Mobile 1 filter. Tranny and rear diff all synthetic. Heavily modded/rebuilt chassis.
Done the GOTS MOD with K/N (MAF cleaned every 6 months like clock work)
Done good tune up (Motorcraft plugs, wires, fuel filter, drive belt, tensioner, both idler pulleys, alternator, all hoses, thermostat, fan clutch and full cooling system flush)
Will be doing the Troyer Performance E-Fan kit as soon as I can get my self to spend the $425 for it. Not on board with the underdrive pulley with all the accessories I have to run....so
I know the next step is the muffler and exhaust Y pipe. What I want to know is what muffler to go with??? I don't want the truck sounding like a retard put a fart pipe on it trying to make it sound like a bad***** V8. It could be silent for all I care. I care about trying to squeeze a little more power out of this chronically underpowered turd of an engine....until I find that magic wrench that turns it into a Raptor LOL!
Also if there is anything within reason that I have missed, please let me know, thanks!

 

Wow, if I didn't know any better I'd say you just described my truck, i've got a K&N CAI FIPK though. If your looking for a v8 like sound for little cash i'd recommend just pulling off the muffler and throwing on a piece of downpipe like I did with mine. Works great, no popping or bubbling when driving and the drone is cancelled out by the KM2's at hwy speeds. True duals would give it a bit of raspy diesel sound. Cherry bomb would give it some poping and raspy noise when revving. Magnaflow isn't very noticable compared to Flowmaster. Overall changing (or removing) the muffler doesn't do anything for power...the cat's would give you the most bang for your buck performance wise.

Youtube is probably the best source for listening to exhaust sounds for this particular model and engine. Hope this helped!

 

I have the same truck and I was just wondering why what you have now is not fast enough?
My truck has more power and acceleration than I can actually use most of the time unless I want a speeding citation.
E fans do help HP and increase cooling to the AC through the condenser, but at a big cost $$$ and I find them very noisy as compared with the pulley fan. I really like a quiet idle.
I bought the truck from the dealer and the guy that owned it before me had already put performance mufflers and cats on it and they sound great. I think they are Flowmasters.
You may want to look into a performance chip too.