95 tahoe vss correction via RPM/VSS Ratio?

[bgwhtahoe]

I have been trying to calibrate my vss on my tahoe for a while. I have put the switches in the vssb and done the calculation to find my new number. Flipped the switches to the correct positions. I have read somewhere that there is something that needs to be changed in the bin. I have found it but i can't seem to come up with a useable number for input with the formula in RPM/VSS Ratio. I am using $od BJYL advanced 0D 251 xdf.
I come up with 40196.913980.......... Not sure were I am going wrong. Do i even need to change this?

8 x numerical gear ratio x 12 x5280
------------------------------------ x65536
512 x 60 tire radius in inches x 2 x pi

8 x 3.42 x 12 x 5280
------------------------- x 65536
512 x 60 x 14.65 x2 3.14