O2 sensor location?

[lnfletcher]

I'm looking at upgrading to a Retrotek fuel injection setup but my main concern is where to locate the O2 sensor. If it is to be located at least 3" back from the header collector, that puts it in plain site on the outside of the car on the sidepipe.
Is anyone running FI and where did you locate the sensor?
Pictures would help ease my fears!

[Voltaire]

I drilled holes and welded bungs into the number 4 and the number 8 cylinder header tubes about 1 1/2" from the end plate. With this set-up your system will only be measuring the 4 and 8 cylinders but I haven't had any problems. If you take your car to get tuned they can correct for this.