Originally Posted by
workingonit
I can only speak from experience with the Tdi300 and T5 Disco. The poly tanks are tough - they can be heated to plastic state and dimpled a bit to avoid coach bolt heads if clearance is problematic. The white plastic sender units are brittle by comparison.
Regarding the Td5 sender you already have? Would it be simple enough to disconnect or remove the motor and replace it with a piece of extension tube to reach the bottom of the tank? The Td5 senders have press in fittings, and the engine has bayonet (?) so you would need to arrange a transition somewhere?
If you are thinking of adapting a Tdi300 sender unit, make sure it can be secured by the Td5 tank ring, as the rings are slightly different between models.
If you make your own (I did, out of steel) you should consider having the frame spring loaded to press against the bottom of the tank to avoid swing fatigue to the tank lid - don't simply suspend your pipes like stalagmites from the roof of the tank if there is any weight at the bottom of the pipe ie filter, pipe stiffening, float and electric resistance board. The return pipe is much shorter than the pickup.