???? Just double checking..... srry.

 

Yep, 3". You can go 4", but IDK if it does any better...Is yours a V6? If so, I don't think that 4" will do anything for you. It's good for the Hemi...but that's all I've seen it on.

 

4.7L Is what I have.

 

Ok then, a 4" may do you good, uhm..there is a thread about making one and its got pics and information, i dont remember who wrote it, but look it up in the search and also Hammer would probably know the difference, you could PM him. But since yours is a V8, the bigger tube would probably be good as it lets in slightly more air, but there is only so much that it can take and it wont take anymore no matter what. so really, it's up to you.

 

3" is plenty for any application, its only going to take in so much air no matter how big the pipe , also 4'' looks offly big under the hood! run the filter int a good location and you will have no problems .

 

Too small is NG, as is too big. Think about an exhaust. Big is good up to a point, but too big and the airflow slows down too much and you LOSE performance.
I don't think 4" is bad but I'd not go any larger. At the same time, I don't think there is much difference between a 3" or 4" pipe, at least not enough to be able to feel a difference.
I use 3" when I make 'em, but 3", 3.5" or 4" would be ok.
Might use a 4" if I was making one for a truck with a wider TB though.

 

I did a 3" pvc on my 4.7 and its good,i wouldnt say i notice anything great but it better than stock. I also have a nice exhaust setup