Help me please!!!!!

[techsan]

You should be able to crank the car without the headers, however its not a good idea to run for long, like you said earlier. In your original post you said you thought the timing was on but it wouldn't even backfire, it sounds like it may be 180 degrees off. You can rotate the engine one complete revolution to get it on the intake or exhaust stroke (can't remember which one you need). Then rewire the plugs and check the timing. I know on a 5.0L there is an indicator on the crank pulley that shows Top Dead Center, it may be worth a shot. Hope this helps.