Re: Fuel pressure readings
My '96 fuel pressure seems to stay around 50psi from idle to hard work. I don't remember seeing much variation from that with one exception: when first starting up, it seems to be a few pounds less until it has run a few minutes.
This data is via an electric gauge. I have no way of knowing how accurate it is.
Further thought: I do have a needle valve in the fuel line to the gauge in order to squeeze down the pulsations of the mechanical fuel pump. Without it, the needle of the gauge would jump from the "water hammer" effect. If that's what you are seeing, then I would recommend installing something to stop the rapid up-and-down needle or risk damage to the gauge.