hello, im in the prosses of figuring out what i wanna do with my exhaust.

i have a 94 f150 351 4wd i wanna put on tong tube headers, two high flow cats,
and two straight through perforated core mufflers. all 3''

my question is what do i get? is 3'' to big for duels on a 351?
if any of you have done this before some of the routing would be awesome

this is what i found so far

headers Hedman 89270 Hedman Headers

cat Magnaflow 94309 Magnaflow Performance Hi-Flow Catalytic Converters

muffler Magnaflow 11219 Magnaflow Performance Satin Stainless Steel Mufflers
or Cherry Bomb 87517 Cherry Bomb Glasspack Mufflers
but im not sure if the cherry bombs are perforated core or louverd

any reply are appreciated

 

I would say 3" is too big for duals. 3" is better for a single pipe but 2.5" is better for duals from what i've seen.

 

Yes, 3" is way too big. Even 2.5" is slightly too large. 2.25" would be better. But in my opinion, running a 3" single would be the best of all. The single 3" produces more torque, better gas mileage, and requires only one muffler. In contrast, the reason many dual systems have 2 pipes is to restore the sound and flow balance that a single system produces anyway.

Those Magnaflow cats are not high flows. They are ordinary 400 cpi ceramic converters. They are the same cell density as the original converters, but about 30% less cross section. That means the stock cats flow better. Magnaflow does make some high flow cats, but they are not very good in terms of theie overall quality. They work ok sometimes, but it is not uncommon for vehicles that use them to fail emissions. I have seen them come apart as well.

My suggestion is do not undermine the very nice headers you are using with a substandard converter. These would be a much better alternative.

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As far as the muffler, I don't like either. The Magnaflows are overpriced and are built from substandard steel. I have accumulated quite the collection of pictures of failed Magnaflows. They tend to develop stress cracks around the neck, which is one of the failure points. They use an inferior stainless. The mufflers themselves are assembled in the us out of prefabricated oriental components.

The Cherry bombs have an aggressive sound but are made from aluminized steel and tend to rot out. They are a louvered design that is more restrictive than most stock mufflers, and they get very loud very quickly as they fail.

The muffler I use myself and the ones I recommend to others are the WickedFlows. They have one of the best sounds. Its kind of hard to describe, but they just have a sound to them that no other muffler has.

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thank for the help. should i go with the round or large body cat?

are the wicked flow mufflers perforated core?

i think im gunna go with bear river. they seem to have pretty good stuff

 

For a truck, I'd go with the oval body cats. They are larger and that should produce a deeper tone, plus they cost less. The round body cats seem to be more for when you don't have a lot of room.

 

I was loging on to ask pretty much the same question.

Using a single 3" design would you recomend 2 cats just after the headers? Or a single after the merge pipe? I will need to pass emissions in Washington state so which is the "cleaner" option?

Also using a single 3" design would you recomend using 3" from the headers through to the merge pipe? Or use the 2.5" reducers and then go up to 3" after they are merged together?


I am considering using spintech mufflers...I have done some research and it seems like they are some of the highest flowing mufflers out there, and they don't have insulation to blow out. Also their super pro mufflers are TINY!

I saw this design they did on a titan and think its really cool looking with the xpipe under the passenger side. However I don't really want to pay for two mufflers and an x and all the extra piping.
YouTube - Titan True Dual SpinTechs

I have pretty much the same setup...351W auto 4x4 ex cab.
I want to improve fuel economy, and make sure I retain my ability to tow.

 

what would you recommend for hangers?

 

I do not recommend the Spintechs. The sound is too loud, at least for me, and they are know to drone and resonate.