Oil sender install whoes

Ok peeps got a problem. Whilst at Gaydon decided to buy an oil temp/pressure sender unit for my golf. It has the dials but not wired up.

Here is the ETKA version of it
http://uk.geocities.com/satelliteone/Image1.jpg

The problem i have is the sender unit is too fat, and it wont  screw down on the oil filter housing because the fuel pump is in the way.

Just in front of the oil switch there is a hole i can tap off. Usually it been plugged, an alan key is needed to unscrew it,  M10 thread

Question is>> did VW make a thinner sender units. Or did they make a T-L Peice for the sender unit.?

>>Also what difference will make if i tap it off from the head, will it read the wrong pressure?

Its 1.6 Carb model, GTi wont have this problem because of the pump is not located at the engine.

Also does any know how to wire up the electrical sender units to the clocks.

many thanks