as for oil pressure lines, i have used tiny hydraulic hoses. way better than that crappy plastic line [which, in my opinion, is good only for vacuum use] and way cheaper than braided an hose. the drawback to this is weight and possible routing issues.
How do you hook up a hydraulic or braided line to a generic oil pressure gauge that only has a fitting on the back for the nylon hose compression fitting cap? I have owned other mechanical gauges that have a different fitting, but it seems most only have the fitting for the nylon line.
