Not certain if from factory or not but all mechanical gauges. Looks like 3 or 4. Need to order fittings and don’t normally work with much under 6.

tks

Never messed with mechanical fuel press hose, but when I replaced the water lines for my helm mounted water press gauges, I used 1/8" plastic tubing from a big rig repair place locally. They use it on semi's for something (seats maybe??). Couldn't find it anywhere else locally.

With that said, some guys like to increase water line dia to 1/4" to help prevent line clogging from sand, rust particles, etc. I'm still considering the 1/4' lines since mine are getting clogged again (slow/delayed response).

Are you running fuel lines to helm for mechanical gauges?

gonna skip the fuel lines although they’re there however I’m not that comfortable with that and engines are just NA. I would however like to hook up the water pressure. Looks like 1/4” hose and not certain of the AN size. I’ll figure it out today. Looks like about the size of a 3/8” bolt diameter .

this might help

Getrdunn - if you don’t have -an wrenches, you can figure out -an size by thread size too. Do google search for sizes. Many charts will pop up.

If a 7/16" wrench slips over the threads but a 3/8" wrench doesn't, you have a 4AN fitting

https://www.pegasusautoracing.com/do...ocID=TECH00096

Lol. Speedy out accelerated me. Lol

Also, AN metal tubing is measured by the OD, and hose is measured by the ID. The -X number refers to the size in 16ths of an inch, EX: -6 = 6/16" = 3/8".
If you're buying hose ends try to keep the hose brand and fitting brand the same.

I just have the female ends but that helped. A 3/8 blot slid in sloppy but a 7/16 given the right thread would be a fit. So what you said yes it’s 4 AN. Amazing when you slip away from this kind of stuff how much you can forget.

Makes sense, I think they were -4AN on my 1991 Cigarette.