Will GM 200r4 work with factory floor shift location?

It dawned on me that I should give my transmission builder a call and run all this by him. He actually advised against enlarging the holes in the fittings beyond .220". He explained that if there is too much flow through the cooling component, the heat has less opportunity to be passed out of the coolers.
It makes sense, since only a portion of the pumped volume is sent out to the coolers at any given time.

I will be making fittings like you did for the radiator hook-ups, and enlarging them to match the .220" size that are on th200r4.

I call it ideal at that point.