You want approx L20 (for 91), R0(for 110)and R10 for 119. The exact spot can vary by +,- 5ish, depending on location. Use a Satfinder to nail down the signal strength. Make sure you also line up the LNB holders according to the above 3 grids on the bottomof the holder. If you purchased the
t55 from the manufacturer you can fill out their form on the website and they email you the exact coordinates. The grids on the holders stay exact and only the placement on the rail changes by location.