Replacement fuel lines

I believe I have a pin hole somewhere in my fuel lines, fuel drains all the way back to the tank making the old girl crank a lot before starting. I have bend and flare tools, can anyone tell me what size line and fittings are needed? I believe both sections of steel line use the same fittings.

Thanks!

most vehicles use 5/16 line (1/2" on the nuts).

My R120 came with 3/8" line. I installed a spin-on fuel filter near the tank and an electric fuel pumps just after the filters. Another feature you might like to install after the tank and before anything else is a check valve. This will prevent run-back.
I am going to include a picture of a pump and filter install. This is on my Cummins 4bta powered L110. I do not have any pictures of the R120 fuel system.
Twin fuel filters for twin fuel tanks. One electric pump for each tank. I used a http://products.pollakaftermarket.com/v ... iven-valve to control the fuel. https://www.summitracing.com/parts/hly- ... SiEALw_wcB
https://www.google.ca/search?hl=en&sxsr ... ent=psy-ab for a check valve.

That is odd, with most of the pipe threaded fittings being 1/8" I'm not sure why they would go 3/8" on the tube? Either will be fine, If my 855 Cummins can live off 5/16" (for the high pressure line") what ever you are running should.
You may be right, Nikki, I may be thinking off my Cummins, I don't think it would matter much which you use. The ID of 1/8" NPT fitting is smaller than either size line.

I recall installing a 5/16th line in the tank, I used 2 - 5/16th male and a coupler to make it work. I am attaching a pic of the {1/4" original minus} the sheet metal brace that was soldered to the tube, you will see it when you get that far.
You might want to install a 6"access hole and a 7-1/2" cover under the seat cushion, so if you have to change the sender in the future it is easier.
EDIT: A guy could make it a one piece pick up tube, you may want to or not solder a brace on it.

My L120 has 5/16 line and 1/2-20 fittings. I recently took them off and they are original. Also there is a short flex line from the hard line to the fuel pump.

By the way Desert Toad, nice looking Farmall A sitting there next to your L. Both look good! I have a 1946 A that was my grandfather's that I'm restoring at the same time as my R112.