help installing tach

I am replacing the tach for a 2004 200hp hpdi and am not sure what setting on the back of the tach to use. The original tach was set at 6 pulses and the new tach settings are:# of poles set, 4-1, 6-2, 8-3, 10-4, and 12-5. The positions on the back 1 thru 6. Any help would be appreciatted.

I think I found the answer on the Faria website. The alternator should be a 12 pole so the setting would be position 5.