96 Tahoe random misfire (no codes) 5.7

My cousin has a 96 tahoe that he's trying to fix. Unfortunately he has fired the parts cannon at it. Can you help me figure out what wrong with it so I can help him? So far he's replaced the following

Ignition Coil Ignition Control Module Spark Plugs & Wires Fuel Injectors (MPFI swap) Fuel Filter Fuel Pump Distributor Rotor Intake Temp Sensor

He did a compression test and all 8 cylinders were around 120psi

It will have a slight miss when idling. When you get on the throttle it worsens. I've cleaned the IAC out and cleaned the throttle body. The distributor cap looked new so we didnt touch it. I also ran some valve train cleaner through it and that did help. I did a smoke test and found no vacuum leaks. He did mention a coolant leak somewhere but we can't find it so maybe it's lower intake gaskets? But I'm not gonna shove parts down it's throat if we can't figure out why it refuses to run right. Anyone got suggestions?