2013 Camaro LS3/TR6060 swap.

Running tach output from pin 48 with a resistor pickup for the signal. I get signal, but it reads too high. I had high and low resolution set at 6, but it was reading approximately 2x what it should have been. I then read that 6 is for 4 cylinder and 3 is for 8 cylinder so I changed to 3 but now it's approximately 4x what it should be, so maybe I went the wrong direction?

Screenshot attached, any guidance appreciated!

Click image for larger version. 

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