Gas Tanks 101

[Tim_Lentz@xxxxxxxxxxx]

     Could someone please educate me on the purpose and functionality of 
     the expansion tank and tubes (and such) that are connected to my 70's 
     spider gas tank (and probably other Alfa's of this vintage). 
     
     Maybe I just need a lesson on "fuel delivery", but at first glance it 
     seems like it's a waste of trunk space. 
     
     Thanks,
     
     Tim Lentz
     '74 spider (under construction)

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