I am getting ready to order my TTI headers . The Part number is 440-200. I have the option of having the O2 bung on the Header collector or on the reducer/adapter. Any preferred spot? I have not been able to find a pic. Maybe @AndyF has a pic? Also what size reducer adapter? It is in a 73 scamp with a 512 ci RB . Choices are 3.5 to 2.5, 3.5 to 3.0 or 3.5 to 3.5?