Porsche 914 to Bug gauge conversion question

Hi RAMVA! As some of you may recall, I decided to install an early 914
gauge cluster on the bug. It's finally in and it looks great. But there
are some issues that must be covered.

Just as Speedy Jim suggested, the fuel gauge is designed to use the can
shaped (Porsche, Ghia) sender which stays level when the car moves, so,
using the stock bug sender makes the needle dance around almost all the
time. Since I MUST change the sender anyway, I'd like to know, does the
Porsche sender fit in the tank? Is it the same length as the ghia
sender? (I heard the porsche sender is 300mm long). The reason I want
to know is because with the porsche sender I can make the red empty
tank light on the gauge work. I don't know if that is possible at all
with the ghia sender.

The other issue is with the oil temp gauge I installed on the upper
half of the fuel gauge. The sender I installed is a VDO drain plug
sender (300F), really easy to install. The engine currently in the bug
is a stock 1300SP with all the cooling tin installed. This engine never
overheats, even when driven hard. But still I find the gauge showing
too low temp. After 4 hours non stop driving at 55MPH it just goes up
to 1/4 of the way to the red area. I'd like to know if I'm getting
false measurements 'cause of the location of the sender (oil drain
plug) or the length of the cable going to the sender (it goes from the
gauge down to the floor behind the pedals, to the passenger side, along
the heater channel on that side, behind the engine, and down to the
sender). Did I do something wrong somewhere?

TIA,
Karls