Fuel leak, I am stumped. HELP!

I have an 87 T1 daytona. I have had a progressive fuel leak. Now it's bad enough that it starts puffing smoke out from under the hood. So of course I drive it limited to my brothers garage and back to try to fix it.
But, I have since replaced the injector O rings, didn't work. Replaced fuel rail, didn't work. Replaced injectors with new/used ones. Still leaks. All hoses are new and clamped well. FPR is fine too. ???
Do I have a cracked intake manifold or something? What else could cause this leak. If this helps, it seems like it is concentrated to the #4 cylinder area where it leaks. Could a blown intake gasket cause this? Again I am stumped. TIA for anyones help.

are you sure it's fuel? fuel goes from the tank, to the hard lines, to the rubber lines, to the rail, to the injectors, to the regulator, then back to the tank. have you tried looking while the motor is running?(stupid question, i know, but it works for me) also, i had my schrader valve stick half way open once. that sucked. get this fixed quickly, because about 1 of every 3 turbododges i see in the junkyard have a melted wiring harness/melted everything else right where the fuel lines run!!!
tony

It's fixed.