Help with my first engine build (5.9 Magnum)

Converters are the magic mystery box of the car world. And they change the technology daily it seems. It’s almost like you can’t get too much converter in anything anymore. The last few I’ve bought the converter guys recommend way way more stall speed than I was thinking. A tight 5000 is now a street converter.
A 5000 tight? For a driver? Dammmmm they must have gotten em really tight!