Ok, I am trying to plumb my fuel line to regualtor. My line is 3/8 I wanna buy some Stainless Braided Hose and Clamps (Earls Eco fit). What do I buy? 6AN or 8AN? What do measure inside diameter outside diameter? Looking at Jegs catalog does not help me. I dont have a palce here locally that I can actually look at the stuff.

Are you saying you want to use a 3/8 hard line to the regulator and what size to use out of it? Or are you saying you want to use a AN size line that you can use 3/8 (NPT) pipe thread adapters to hook up using 3/8 NPT to either # 6AN or #8 AN adapter fittings?

My line coming from my tank is 3/8, from there I wanna run some braided line to my regulator, it has a 3/8 npt nipple, what size hose do I need to mate them together?

AN lines are based off 1/16th" incriments. IE, -4= 1/4, -6=3/8's, -8=1/2", -10=5/8's etc.

You would need a -6

Thanks Wild Bill!

They make a 3/8 compression to #6AN fitting OR you
can use a flair fitting to #6 AN
EDIT
then on the other end of the line that will mount to
the reg you can buy a #6 AN line that goes to pipe
this fitting will be 2 parts that you install on
the braided line.... same set up for the other end
for the 3/8
This is for the 3/8 hard line
www.summitracing.com/parts/EAR-165006ERL/
This is for the reg or pump
www.summitracing.com/parts/SUM-220648/
You could use this if you want to go from the 3/8
tube to a male #6 an then the braided hose would
have AN females on both ends
www.summitracing.com/parts/RUS-639210/

The inside diameter of the a/n fittings is smaller than the ID of the hose. Keep this in mind. I would use -8 to more correctly replicate the 3/8 line out of the tank.

looking at that chart, 8AN would be way to big, I cant see the hose being that thick and fitting snug on my fuel line. Double checked at O'reilly with some 3/8 fuel hose and it fit right on. Atleast now I know what AN stands for Army Navy, I learned something today and its early.

Just remember that HOSE is measured ID and TUBE is
measured OD