oil gage sending unit 77 and later
0 psi 234 - 246 ohms
20 psi = 149 - 157
40 psi = 100.5 - 105.5
60 psi = 65 -69
80 psi = 32.5 - 34.5
 

Oil pressure sending unit: 75 and 76
0 psi = 68-78 ohms
40 psi = 21-25 ohms
80 psi = 7-13 ohms