If I were the “project engineer”, in basic terms.........it would get as tight of a 9.5” or 10” converter as one of the more respected companies would build.
With that sized converter, behind that motor, in that weight car, with real street gears(3.23, 3.55, etc)........ even a really tight 9.5-10” unit will still stall at 3500-ish, or more.

Most off the shelf street units aren’t designed with 600+ Ft/lbs in mind.

If it wasnt built specifically for a stroker with that kind of torque, I’d just send it out now and have it adjusted before I bothered putting it in.