I have a 4 banger stang that will do that all the time, ive idled it for a long time with no pressure and nothing has happened. I would bet that its your gauge. Have you heard any noises when it was at 0?
My dad's GT does the same thing. When I am stopped it reads at the L in NORMAL. I noticed that the volt gauge does the same, but the fuel and water gauges do not. My 89 LX does the same but with less variation. I don't like the gaudiness of aftermarket gauges but I really want to know what my oil pressure is at.
yep, get a real gauge. you can try a new sender for the oem gauge, but you cant polish a turd.
get a real gauge and know for sure. the stockers are famous for being a little less informative than an idiot light.
I believe stock idle oil pressure should be like 15 psi for a F.I. 302, had this problem once and it was the stock gauge. The gauge reads in a zone, if you drop below that zone, it drops straight to zero, whether there is really pressure there or not.