1997 5.7L multiple cultures misfires

Did you use a gage and check fuel pressure? For the spider fuel system, koeo, 60--66psi. A non-invasive way to check for spark is to use a digital multimeter, engine idling, touch lead to spark plug wire, Don't penetrate the insulation or take the wire loose, it's an inductive reading. I've seen readings like .6 or .7 volts, also, seen reading bouncing off zero, no spark with that zero reading. You could do a cylinder balance test, engine idling, kill cylinder, one at a time, fuel or spark. If you kill a cylinder that has no effect on the idle rpms, that cylinder is dead, then check fuel--spark--compression on that cylinder. If you kill spark, do it quickly so you don't flood the cylinder or just kill fuel on the cylinder.