I am having some difficulty with my new fuel tank for my 81 Vanagon.

The tube on the bottom that goes to the fuel pump /filters, is much bigger
that the original unit.  I put 1/2 inch ID heater hose on it for r now, and
put the other original fuel line inside of that and crimped it and it is
working for now.

Does anyone know what size fuel line this is(cannot find it locally), and
also a need to "reduce" it somewhere before the fuel pump to accept a "t"
for my auxiliary heater and also my fuel pump?

TIA
Adam Puzerewski
81 westy
74 beetle
86 cabrio
Vanagon Partsmobiles