My dad's 90' did the same. Fuel pumps both powered up but wouldn't start. Replaced the fuel pump selector switch on the dash and that solved it.Haven’t had much time to mess with it today. Rear fuel pump powers up but still no fuel to the motor. It does start on ether though. Valve train sounds good.
I’ll pull the filter off and see if it’s getting fuel to there next.
260k on her