just picked up a set of headers today for my 08 4.8 truck. question is should I run 3" y pipe or should i run duals with an x pipe? i got headers only so id have to make the rest anyway.

here are deciding factors.

motor will eventually be cammed 220 to 224.
stalled to around 3400.
probably a hit on the bottle.

ive got a 3 inch spintech on the truck now and also have another brand new matching spintech. if i were to run the duals id like to use these mufflers but feel that dual 3" is a bit much. id also like to put cutouts on it but that will start getting pricey. also want stainless tubing so more $$. but i do love the sound of duals with x pipe. so if this were you what would you do?

also i love the magnaflow stainless bends cuz they are super cheap but i cant seem to find straight sections from them.. who do you guys use? and who for v band clamps?

 

Your going to have to answer your own question. Dual 2.5's are going to be louder than a single 3".
they'll flow close to the same. Just depends on how loud you want it.
Duals you'll need 2 cutouts, singly you can use 1 behind the Y.

 

ENGINE SIZE HORSEPOWER MUFFLER INLET/OUTLET
Single Exhaust Dual Exhaust
150-200 CID 100 to 150 2" to 2-1/4" 2"
200-250 CID 100 to 200 2-1/4" to 2-1/2" 2" to 2-1/4"
250-300 CID 150 to 250 2-1/2" to 3" 2" to 2-1/2"
300-350 CID 200 to 350 2-1/2" to 3" 2-1/4" to 2-1/2"
350-400 CID 250 to 550 3" to 4" 2-1/2" to 3
http://www.magnaflow.com/07techtips/faq/question10.asp