I personally would go 2 1/2 in and 2 1/2 dual out. Thats what i'm going to do. keep the stock cat.

 

Spintech Super Pro Streets sound awesome on 4.3's.theres a vid on youtube of them on a s10 pickup dualed and they sound really good.thats what ive on my 02 blazer xtreme but single but still sounds mean as hell.

 

bigger piping = deeper sound (according to muffler shop). i have 2 1/2" in and 3" out with the 40 series muffler (more popular one as far as ive seen) and it sounds really nice and deep all throughout the rpm range. if you really want the v8 sound get the highflow cat, instead of a smooth deep sound, the high flow cat gives a little deeper and raspier tone like a v8.

 

What hi flow cat do you have, and did it make the check engine light come on from the o2 sensor?

 

i have the magnaflow high flow cat, which is a OBD2 cat so no it didnt make the light go off. ill try and make a new vid here soon with the difference in sound.

 

I built custom exhaust

used factory manifolds that I opened up and smoothed inside and out. 2.25 in tubing to dual in/single out cat (welded bungs where needed for O2 sensors). then 3 in to american thunder muffler

sounds mean at idle--- scares kids, old people and the neighborhood dogs away when I punch it

 

Rottidog was tellin me yesterday you can have your upstream o2 sensor disconnected so you can run whatever cat you like

 

you mean the downstream o2 sensor? in other words the o2 sensor after the cat.

 

Ya that's what I meant.

 

super 44 is best