Oil Temp Senders

[karmannkombi]

does anyone know what VDO oil temp sender unit I can use on my 72 Van 1700 motor? I dont want to use the dipstick model because theyre not very accurate, and I've heard the drain plug model doesnt work on the Type 4 motor (ie 1700, 1800,2L van motors from 72 onwards). I have heard something of another sump plate with a special hole drilled in it to accomadate the drain plug sender for these motors (avialable at Bus Boys) but im not sure whats different about it.

Why exactly does the drain plug sender not work? And where do they place the new hole?

Has anyone installed an oil temp gauge on a 72 or newer bus and have some suggestions?

[BUSDADDY]

Not DVKK but Porsche puts it in the round plate below the dipstick (right rear corner of the engine, 2 6mm bolts) Personally I'm not convinced it's the best place for a real time oil temp reading as there is not much action off in the breather tower. I brazed a boss into the sump plate beside the retainer bolt so the probe goes up inside the screen. Not the best for off road action (a little vulnerable) but I like to know what temp the oil is in the sump before it hits the cooler, pump, etc.. I like to belive I'm getting quicker results on a long hill or when pushing 75+ than waiting for things to soak into a corner of the engine with no significant flow happening.
Somebody please prove me wrong.