who knows what size the exaust is before the muffler on stock 4.2L?? im tryin to buy a Flowmaster for it but i wanna go 1 in 2 out and the only size i can find is 3" in 2-1/2" out i dunno what size it is do you??

 

It's either 1 or the other. I'd think it was 3" before the muffler. Check with a local muffler shop, they should know.

 

James,

The Flowmasters are all the same. I have the same one your getting. The one in and two out. They are all the same size.

The muffler shop that installs it will make it fit right. mine came out perfect.

tom

 

Yea, that sounds about right. My old Chevy truck was the same way. I just wanted a Flowmaster muffler so they put one on with no additional piping. Good answer Tom and keep on keepin' on or whatever!

 

kool thanks for the replies i called Ford and they said its 2-1/2 before the muffler, but i guess the 3" inlet will be ok cause thats all they come in

 

Yeah, they'll slide it right in then weld it. comes out perfect trust me.

 

do you have headders??

 

I have headers, let a pro shop install, dont waste your time tryin to make sure its perfect. Took me 22 man hours.

IE 2 of us worked for about 11 hours on a saturday

 

Yup, plain and simple headers for a 4.2 are a pain to install. Have a shop do it.

 

Unless someone can show me before and after dyno results on headers, I just don't see the need.

Even on the header websites, no where does it even claim that the headers will make a performance difference.

And usually, when your buying some sort of performance product, they will always speculate aproximately how much hp gain you'll get. But the header sites say nothing.

I don't think, in my opinion, that headers will give you any performance gains over stock. I guess unless you do major internal work.

Tom

 

Unless someone can show me before and after dyno results on headers, I just don't see the need.

Even on the header websites, no where does it even claim that the headers will make a performance difference.

And usually, when your buying some sort of performance product, they will always speculate aproximately how much hp gain you'll get. But the header sites say nothing.

I don't think, in my opinion, that headers will give you any performance gains over stock. I guess unless you do major internal work.

Tom

 

Click on the Cat4ward link towards the bottom. Any internet site will tell you what the claims are. With the JBA 14 Ga. headers, you can expect between 15-20 HP and 20-26 TQ. Besides, if you have a less-restrictive header, wouldnt exhaust move easier, making your engine breathe better? Just my $.02

Garrett

 

Also, on the JBA website, they have d a link for "dyno info" Although they dont test our engine, the 4.6 cobra with headers gained 10 HP and 11 TQ off the dyno.

 

This is true in some applications were the headers have many right angles. My headers, however, already look very large and smooth. I don't always beleive what the manufacture claims, after all, the Tornado claims like 8 horsepower and the throttle spacer claims even more, and both of those are bull.

Ah, and remember the lawsuit against Splitfire spark plugs. They got sued for making false claims on horsepower increases, and lost.

So, lesson to be learned here, don't believe everything you read.

Besides, If it aint going in any faster, than it ain't going to come out any faster either.

On the other hand, your headers will play a larger role AFTER you install the S/C.

But right now, I don't think they're doing anything.

Tom

 

Ah, Garrett,

They ARE beautiful though. Very tasty looking. Here is a good picture. Not too pricy either.


http://www.centuryperformance.com/de...ct_ID=JBA-1672