There is a thread on here where I give the part number for a 3 prong sensor like you are looking for, it is a wells ps128. You have to get an adaptor fitting to adapt the switch to the metric port on the block. I got an adaptor kit with various adaptor fitting in it to match up the port on the block to the switch. Best way is to go to a real auto parts store like napa that has fittings in a drawer with the oil light switch from the block and the switch and get an adaptor that matches up. I have run this switch this way on Geronimo for 31 years, and the only problem I ever had was the switch failing, not the fitting leaking.