PK numbers

I've wondered, how high is high stall and how low is low stall..I've talked about this truck and what I want to do with the engine several places here in pretty good details
85 d150 long bed, building a forged crank slant 6 to replace the weak noodle original slant that is in there now. The truck came with the 727 and 3.21 which will both stay. Only reason I'm asking about converters is because listening to it start I think it has a bad ring gear. Otherwise I would have never brought up anything about whether I have a lock up or not, or anything about replacing the converter. I have swapped out starters to see if that may be the source of the noise with no change. As long as the engine is coming out that's the time to check it out and replace the converter if my fears turn out to be true. Will have a super 6, stock exhaust manifold hogged out to match the flange gasket, 2-1/4 all the way out. Oregon 819 reground cam, ported peanut head shaved for 8-1/2 to 9:1 ported and oversized valves. 3 season daily driver, want to be able to pull a 3000# popup with some camping gear in the bed. I am building towards stock for 85 360 hp numbers.