Should I replace the Timing Chain?

I have a 1992 Ford Explorer 2Dr 4WD AT with 4.0l V6. The V6 won’t start. I have checked the computer and there are no codes. I can hear the fuel pump run. I have verified with a timing light that the ignition is firing. I have put fuel past the throttle body into the intake manifold and cranked the motor. I see the timing light to flash, but no ignition. I am sure it is getting air, has gas, and has spark. The only think I can think is that it jumped timing. I just don’t know if this is an interferance engine or not. Will the valves hit the pistons if the timing jumps or the timing chain breaks? I haven’t heard any noise while cranking. Occationally it will spit but never start. I do smell gas out of the exhaust so I think the chain is not broken. I’m willing to change the timing chain, but not willing to pull the heads and rebuild the motor if the whole thing is toast. Is there a way to tell if the motor is out of phase? It doesn’t have a distributor. How much out of phase does it need to be to not run or bend valves?

Break down and buy a $20 compression gage at your local auto parts store. This won’t tell you if the timing is correct but it will verify that the cam is turning and the valves are operating with the least invasive diagnostic method.