What rpm stall converter should use?

Yes it has, tremendously. You can get a converter that'll flash to 5K in your combo, but be tight enough to drive everyday. It's the one BIGGEST mistake people make when making a choice. People think the converter will slip all the time like the old days and that's just not true anymore. As much as it's preached on here and people STILL want to put crappy 2500 stall converters in things. That'where the factory converters stalled.
That’s what I Remember , In the later 70’s I had a 3000 stall converter in a 1971 340 Duster and there was a lot of slip on normal driving.