Inliners International Forums General Discussion Engines tossing around the idea of efi for my 235

This is currently where I have the narrowband O2 sensor. Just a stock GM replacement that goes to the ecu.
http://i175.photobucket.com/albums/w124/rockfan1815/final%20tbi%20conversion%20pics/100_0862.jpg

I was wondering if it would be better to mount it closer to the header or in the header at the collector.
http://i175.photobucket.com/albums/w124/rockfan1815/engine/100_0094.jpg