Here is a picture that shows the engine cylinder adjustments if you want to diy install an Autogage 3 3/4″ tachometer for operation on 4 or 6 cylinder engines. By default this tachometer is factory calibrated for 8 cylinder engines, then a switch adjusment must be made.
It is shown that for 4 cylinder the both switches are down, 6 cylinder – switch number 1 down, switch number 2 up, and for 8 cylinder the switches up for both.
The picture tells you to locate the switch on the circuit board after removing the back cup of the tacho. Move each of the two switches to the proper cylinder selection according to the diagram illustration above.
