First off you need to fix that fuel leak, or you won't have to worry about the misfire long, lol... The wispy smoke from the covers could just be old oil burning off from the install.
You really need to check the compression again. That is a huge difference. Heck, just for grins double check that you have the spark plug tight in the head. Could just be that simple.
If you want to check to see if the injectors are sealing you could spray some carb cleaner around all the injectors where they go into the head and see if the motor changes tone. If so, then that's a vac leak.
