fuel lines diameter? Post Posted 07 May 2018, 1:57 PM #1599018 (In Topic #217479) lukecab Settling In Hi all looking at renewing the metal fuel lines under the car from tank to bulkhead but don't know what size kunifer pipe to buy 6mm or 8mm.cheers 0 guests and 0 members have just viewed this: None. Forum home Helllllpppp!!