The subject says it all

My ute has what looks like 1/4 inch fuel lines but the CA18 looks to have 5/16 and the R31 fuel tank looks like 5/16.

does it matter since i am not going turbo?

it will probably survive without larger fuel lines. but probably easier just to run the larger ones so that all the fuel lines are the same size. as pretty much all EFI cars run 5/16th fuel line

its not like steel fuel line is expensive

Yeh definately! Also 30 odd years of fuel run through them I'd replace them regardless and start fresh! I have a roll of 5/16 steel line I could sell you. Not exactly sure how much I got but I could check.

Thanks for the offer, I will have a hunt around my area first (It might not be worth the postage)

by the way ... how do you make the bulb on the end? - I suppose that's another tool?

Yeh no problem, I've only ever just flared the end like a brake line. Never had one leak yet.

I've never worried about flaring them. Never had a fuel leak with 40 odd psi fuel pressure. Not even that time I forgot to do the hose clamps up

best to borrow a good flaring tool, the cheap ones are useless and the expensive ones aren't worth it for one job

you should definitely flare them! that's a risk not worth taking pig dog!

also the original fuel line 1/4inch makes for a handy return line... you will need to add one of them anyway

ok cool,

I just need to go buy a few meters of 5/16 and bend it up

then i can get back to wiring ... oh joy

The original line does make for a good return line and also makes for a good template to bend one up the same. Good luck bending a 5/16 line without the right gear it will just kink and become useless. Also another standard line is handy for the cannister return as you need it for EPA.