im getting the at3030 muffler next week and i want to order a y pipe as well.i was told i need a 3" y pipe (in and out) so i found these on ebay.anyone know if this is what i need? i have a 05 quadcab 4.7 v8 4x4 with stock exhaust as of now.im keeping it a single in/out exhaust with a at3030 muffler.should i have a muffler place fab me a y pipe or can i use these ebay ones?

Magnaflow Stainless Y Pipe Single 3" dual 3" : eBay Motors (item 370210653937 end time Jan-29-10 06:22:01 PST)

3" / 3" Y Pipe Universal Custom Exhaust : eBay Motors (item 200427271050 end time Jan-21-10 15:09:03 PST)

Heavy duty exhaust Y Pipe 3" inlet dual 3" outlet : eBay Motors (item 370209922621 end time Jan-27-10 12:09:52 PST)

 

you can go with a 2.5", that's what your piping diameter is for the 4.7

 

Not sure about the 05 4.7L but my 08 was 2.5" in and 3" out and I went with the magnaflow Y-pipe. Only way to truly find out is to get under your truck and see if the inlet pipes are narrower than the exit pipe

 

I asked the same question for my 03 4.7 and the y pipe in the stock exhaust thread. I was looking at this one. its 2.5 in 3 out.

http://www.summitracing.com/parts/MPE-10778/?rtype=10

 

i was told my piping was 3" up to the exhaust and then 2.5" out to my 3.5" tips...thats a good price on a y i might have to look into that....

 

ill go measure it now before it starts snowing