T-727 Problem
Some perf. converters are more prone to draining back and that's what sounds like is happening. Trans-go makes a kit that is a modified manual valve to install in the valve body along with a couple springs and such and it'll solve the problem cause what it does is allow fluid to pump in park. Or if the trans works fine other than that problem you can just start it up and slip it in neutral for 30 seconds each morning and allow it to fill the converter and then drive off. That's what I do and have no problem with it. To me it's no big deal. My car is so cold natured it won't idle until you hold it at about 1200 rpm for 2 minutes so while I'm warming the engine I have it in neutral. Then by the time the engine is warmed up it drives off just fine.