I need HELP

Ok, I'm trying to help my stepdad with his problem. I know nothing about Chevy vans or trucks, I'm a dsm enthusiast so I have no clue about what could be wrong with his van. His problem is, fuel is dumping into the carb not allowing it to start. He has replaced the fuel pressure regulator already. Trying to find other sources of the problem. The van is a 1995 G20 with the 5.0 305 engine.

Does it have good hot blue spark to all spark plugs?
What is the fue pressure reding?

Is it getting spark? After it cranks a bit and you pull a plug, it it wet with fuel?

Good hot spark to all plugs?
Got compression?
What is the fuel pressure running?
Blow out wet cylinders and try some new plugs.

Is it a TBI engine?
Is the injectors or TBI leaking raw fuel down it.
Ot is the injectors spraying fuel into it?