Hi,

More VW related experience. If you go with a T at the oil pressure fitting then you create a dead-end of sorts where the oil being measured for temp is not in the flow. The VDO dipstick sender common to VW upright (tyoe1) engines is not long enough for the B23 motor. In a VW motor, sensing from the sump plate(there is no real oil pan per se) is a good way to do it as the hot oil coming back from the heads down the push rod tubes is what get measured. I do not know the oil flow pattern in the B23 but I would be that the pan is the end and the beginning of the line in the oil circuit so that would be a good place to put it.

One final note - for the VWs we drill a separate hole in the sump plate instead of using the sender to replace the plug. There is simply not enough meat in the plate to tap for threads.

Good luck
Chris
'85 245
'68 VW bus