Just for everyones info, I recently upgraded the exhaust sys. on my 93 F250s/c 460 e4od 2wd. Short headers + new Dynomax single in dual outlet muffler that retains the stock dual tailpipes. This is what I have noticed after aprox 1,000 miles of driving:

Hills, the same hills that the truck used to downshift out of OD to maintain 65mph on the cruise control with no load in the truck, it now climbs those hills without downshifting.
MPG, increased from 10.5 to 11.7
Performance, truck just generally feels stronger and now climbs the steep driveway into the property at idle RPMs, where before it just sat there!

Note: Exhaust system still has stock cat. and Y pipe, with no other mods upstream. Not immense gains but they are noticeable. Cant wait to put the cabover camper on tow the boat and see if the truck runs better under load!...........So far, seems like money well spent!

 

Ditch the stock y-pipe and you will really feel the power. On my F250 I got shorties, custom y-pipe, high-flow cat, and a custom 3" cat-back with a Flo-Pro V7 and I have noticed a pretty good bump in power. I will get long-tubes when I rebuild the motor and restore the truck (I want the 408 stroker!), but shorties have boosted my mid-range power really good. I got better power in the RPM range I'm running when I'm pulling 6,000 lbs on the hills, the can now pull 3rd instead of dropping into second. Not to mention it sounds like a beast with a nice deep exhaust tone.

Enjoy your new system, when you get rid of the stock y-pipe and that little *** pipes behind the muffler it will wake up even more!

 

Not sure what the intake hose looks like on that year, but my '96 F350/460 had the twin shotgun looking intake pipe. Take it apart at the center piece and cut the "airhorn" pieces off. You'll see what I mean.

Have you unplugged the pin and bumped the timing? Should make a noticable gain in lower end power. Stock is like 6 degrees, I put mine at 10 and Wow!

 

im curious, does the 351 have the airhorn in the intake too?

 

Right now, I am not gonna mess with success. The MPG I am quoting is 11.7 combined city/hiway, which aint bad for a 460!. And the power is definitely there ,as the guy in the camry who was riding my bumper on the freeway onramp can attest!, I think that was the fastest 30 to 80mph I have ever seen in a 6,000lbs truck!

 

i think it depends on the year, or basically whether it has speed density or mass air, the mass air equipped trucks have one larger tube that splits into two smaller ones just before the throttle body

 

When my '96 was stock it had horrible acceleration(even with 4.10 gears). Couldn't break the tires loss no how. Was told about the air horn and the timing and when I did the changes......WOW did it wake it up.

My '96 had twin air intakes from airbox to throttle body. The plastic connector in the center had these restrictions build in. Cut them off and you'll have full size intake thru the hoses. I guess they are for "noise" control more then anything? It removes that big "4bbl sound" when you stomp on it.

I put a big turbo muffler on mine and it got average 10mpg daily. There are pictures in my gallery, though it shows it with Vortech supercharger already installed!

 

Not to hijack the thread, but I was told that superchargers don't work well with speed density systems. Is this bulls***? If true, how did you get around the problem? My dad has a '97 F250HD with the 460 and he wants a supercharger.

 

I drove the truck daily for over a year that way(and pulled my 40ft trailer on the weekends). Ran like a raped ape for a big truck. Took it to the drags once and it went 15.8 which back in the day was nip'n on the heels of a Lightning. The worst part was getting the E40d to shift properly. Tried a shift improver gizmo but it didn't work for nothing. Never did much other with it and then traded it in on a '99 V10. Man, I miss that truck!

It was a pretty simple weekend bolt on. Vortech had everything for it in one box, the hardest thing was removing the pass. valve cover to install the drainback fitting for blower. By Sunday night I was out cruisin'. Had this little "whirl" noise under the hood and the big Dynomax turbo with turndown gave it a really nice rumble. 5# of boost and it would scream. Around town, just 1/2-1# would get it away from a light pretty quick.

Did I mention..................I really miss that truck LOL!

 

did you have to run premium gas in your pickup? Have been wanting to put a blower on mine but dont want to pay the extra 30 cents for premium. Here in Nebraska our cheapest gas is mid grade which is 89-90 octane would that be good enough. This would be for 5-6#boost