Outer Limits 4x4 Board

guys have abit of a query with changing the filler neck on my 80 its been cut into a ute and still runs the sedan filler and takes about 10 minutes to fill cause the safety keeps getting trigered. the neck is just floating around so i want to make it straight up from the tank and mount it into the tray..
now the question is what metal tube do i use? will exhaust tube be alright or will it rust? i was thinking with the diesel going through it it shouldnt rust but need to be sure... any ideas? cheers

IMO go for aluminized exhaust tube and should be sweet. like you said diesel will stop rust on the inside anyway. I reckon where the tank breather tube ends on the filler neck needs to be as close to the end as possible and on the upper side of the filler neck. Also the straighter the filler pipe is the better, specially at the top end.
did this on HQ panel van years ago and made heaps of difference.

Ive made heaps of these. Exhaust tube is good as it comes in many sizes and can be flared if needed.