need help with exhaust

[bigtfw2000420]

got a 98 k1500 5.7 and i still have the factory exhaust for now just want to put muffler right now i need to know what size pipe i have and mine is dual in single out and what size pipe is the dual in where my pipe spilts into two into the muffler i know it looks small but dont know yet any help would help

[BLAZER87]

I have a 99 Tahoe with the DI/SO exhaust. Here is the muffler I bought, little shorter, but then I had to use a short peice to connect with tailpipe. It is reversible, so the front two pipes slid right in, I happened to have a piece of pipe that fit perfect in the muffler, but I had to use an expansion tool to very slightly open up the rear taipipe, still have to beat in my piece some, but worked.
http://www.magnaflow.com/02product/shopexd.asp?zone=main&id=848

[bigtfw2000420]

yea did you slide the muffler inside the pipe i thought the further back you go the bigger the pipe you got to put on