It's probably pretty loose then as in the engine will rarely go below 2000 RPM unless it's idling/not under load. I had a similar converter in my Duster and took it out because the slippage annoyed me. I will probably put it back in when I swap to a bigger cam though it did work as intended.
As long as you put in an auxiliary transmission cooler (and deep pan) it doesn't really matter how high the stall is it won't fry the tranny. I don't think you need more though with a 440 it'll definitely stall closer to 2800 than 2400.
