350 TBI uses an in tank pump to provide about 13 - 15 lbs pressure at the TBI unit. Pour some gas down the throat of the TBI and see if it starts - while it runs for a few seconds, check to see if any amount of fuel spray is coming from the 2 injectors inside the top of the TBI. I had this same problem, but it was the alternator wire from battery to alternator had burn thru, had to repair (solder and Tape) until I could replace this wire. It worked for me. If this working, there will be a continuous fine spray in a cone shape. If not, since the fuel filter has been replaced, you likely have an intank pump that has quit or almost quit. Check that the fuses, wiring etc are OK back to the pump. Next step - remove the tank and remove the pump. You can check it on the bench to see if it will turn over but likely it is toast.