Yeah the duals will "flow" better, but without the supporting mods it's practically useless for the increased flow. Just like everyone else said/is going to say... 3" single dumped or 2.5" duals dumped. Or you could just run open headers, easy to pass smog.

thank god someone on this board agrees with me on tips

 

So it wouldnt hurt it any buy runnin duals.... I just thought i would lose 2 much back preaure since it being a 4.8

 

You certainly can if you go too big. I'd say for 4.8's with light to medium bolt-on stuff, 2.25 duals would be the way to go if you must. A 4.8 with full bolt-ons and a cam would likely benefit from the increased flow from 2.5 duals, bet even then, its still only 293 cubes. The 350 in my '66 truck is a 400hp, 415lb-ft motor and is going through 2.5" duals, so you'd have to really push a 4.8 pretty far, IMHO, to absolutely need that size of duals.

In any case, if you size you stuff accordingly, it all works out in the end, be it single or dual.

 

IMO, it will hurt...especially if your pipe size is any bigger than 2.00 or 2.25" inches. Just my opinion.

 

3" single is all you'll need.

 

you can't go wrong with y pipe and single 3". I am doing x-pipe and 2 1/2" dual, but only because i am planning for the future!
go magnaflow.

 

i ran 2.25" duals on my 02 5.3 turned down and didnt like it....i went with a single 3" and love it, it seems to run better off the line and top end and i ran the pipe up and over the rear axile so there is virtually no drone in the cab at all.....

2" is 3.14 square inches
2 1/4 is 3.98 " "
2 1/2 is 4.91 " "
3" is is 7.07 " "

and as you can see there is only about 1 square inch difference between
2.25" duals and a single 3"......

 

The stuff i have done to my truck is long tube headers, cold air, mass air flow, 4.10s, and a tune. I was told that if i had headers then duals is the way 2 go.

 

Don't dump them! I did on my truck and it was so loud in the cab my kids didn't even want to ride with me. Run pipes out the side behind tire or out back to save your sanity. Single 3" or duals 2.5" both will look good. If you do any future mods your covered

 

i have been running 2.5" true duals on my stock 4.8L for 3 years now!!!

never regretted it, always loved it!

dual 2.5" sounds great on a 4.8L, and in winter I get wicked smoke rings at 1300rpm!