they make a adapter for those, So you do not have fuel up to the dash. Just like inside cars. It has fuel up to the isolator, then has antifreeze up to the dash where the gauge is.

http://www.summitracing.com/parts/at...FatcMgodFDsAag

now that's not a bad deal there. but I can buy a new gauge for less. I cant decide on this one.... I am thinking a new gauge which sucks because this one is new in the box

Don't know if you know this but boat manufactures install mechanical gauges on new boats. New boats go through a coast guard inspection. If its good enough for the coast guard and boat manufacturers it's good enough for me. As far as wires in the dash yes they have alot I know I've completely rewired boats and will say this if you have an electrical fire your probably not gonna put it out don't think it matters if you have fuel or not.

auto meter makes an isolater so you do not have fuel all the way up to the dash area plus its a a lot cleaner look i just installed a manual gauge off of my fuel rail you have to have the hatch up to see it but i thought it was a lot easier

Actually, with my track record on motors the last two years I thought about looking into this..... LOL!

I run mechanical gauges on my separator housings in the bilge. Mainly for tuning and trouble shooting though. Oh, also twin small block setup, so no high dollar stuff!

If you stick with a low pressure carb set up I wouldn't see a problem so long as everything is properly attached, however if you get your fuel injection set up going & have high pressure fuel going up to the dash I would want proper line & fittings as recommended by gauge manufacturer. Randy

electrical is the way to go.