I have owned 4 street rods with small block chev engines. Every one had really low oil pressure at idle when the engine is warm. These are not old or tired motors either.  My latest is a 47 ford with a Chev 350, 700R and 3.00 gears. 23K miles. No bad engine sounds, and it doesn't get hot. But the oil pressue is low at idle just like the other small blocks I have owned. When cold, the oil pressure gauge (electric) reads 35 to 40 it will stay some where between 25 to 30 driving at a steady speed and will increase if I increase speed. At idle it drops down to *** near zero. Then when I touch the throttle the oil pressure comes back up. I have been told that low oil pressure at idle when warm is normal for stock small blocks with stock oil pumps. They said as long as the oil pressure comes back up when you depress the throttle it's okay. Is this correct ?..what say you, out there ?...any opinions ? Thanks, Ted  

I was told by a cam manufacturer that hyd. lifters need between 12 and 15 pounds to stay pumped up or they start to make noise. My 406 drops to 0 (manual gauge) after warmup at idle but no noise. The car doesnt overheat and like yours it runs about 30 pounds while going down the road. And just like yours the pressure will come up when giving some gas. I'm afraid to drive it like that, thinking I should just rebuild it. I have own lots of chevys over the last 35 years and this is the first one that has 0 oil pressure at idle and no lifter noise.
Quigley