Try to keep them away from the open air of
the collector.. also keep them upstream of
any input air like a evac.. make sure they
point a little downward so if they get any
condensation on them they will drain off..
what I do is put them in near the front of
the collector but have some space so the gasses
mix before it hits the O2(your after the averages
of that bank otherwise you would put one for each
cyl)