I'd suggest getting a 3" DP from a vendor.
Better fuel mileage and a little more go.
Also welding onto rusted pipes doesnt work well.
Here are the ones for 3" pipes:
MagnaFlow Catalytic Converters - 49-STATE & CANADA Catalytic Converters For Trucks, Suv's, American Muscle, Diesel, & Sport Compact Vehicles
And if you want something smaller you can try this:
MagnaFlow Catalytic Converters - 49-STATE & CANADA Catalytic Converters For Trucks, Suv's, American Muscle, Diesel, & Sport Compact Vehicles
Just to give you an example of how inexpensive they are:
Amazon.com: Magnaflow 99009HM Universal Catalytic Converter (Non CARB compliant): Automotive
With ZZP be sure to select the offroad pipe and select the add rear O2 bung for off road pipe.
