Stall Speed Recommendation

I am rebuilding my 727 putting a new convertor in my 71 Dart (Factory Weight) with a 440/727. The engine Im guessing is about 400-425 (.30 74 truck motor, 915 heads (no work just 2.14's and large exh valves, decked) .540 hydraulic roller cam, M1, HP Ultra HP and MSD ignition locked out and a NOS 100 (for this time). No dyno numbers, so this is a bit of a swag. I take this engine to 5900/6000 (cast crank and factory style cast pistons)

727 is a reverse manual VB, going with Red Eagle bands and clutches and sprag upgrade, deep pan.

The rear is 430's with a 295/65/15's. This car is track first, cruiser second. All the other 440's I have dynoed in the past have been a little more beefy than this one and max torque has always been close in the 3800 K range. With that, I am thinking of a 3800 to 4000 K convertor, preferably closer to 4000.

What are your suggestions. Insights etc. I would like to go to a 200 HP shot once I get the NOS worked out. I get the cast crank/piston issue, but not the scope of what I am looking at this moment.

I do appreciate the insight