03 V6 Exhaust Dimension

[Colorblind and distracted]

Hi, I am a student welder and I have a 2003 v6 for my daily, and recently during an oil change after winter, I found my exhaust is rusted and loose. So I decided to make a true dual straight pipes. Could anyone tell me the dimension of the stock exhaust system? Or the dimension of the dual exhaust for v6 for those who have already done it? Thanks a lot in advance.