Torque Converters

I'm still not quite comfortable with my knowledge in this subject area, so here is/are my scenario(s).

I have determined my cam and pistons for mild 318 build, the cam specs say "Will work w/stock converter" stall

What is the stall of a 1965 904 stock converter?

What is meant by "flash"

Also cam specs say "mild stall would benefit" cam....but stock OK...

What is "mild stall"?

My original objective (gears) was to be around 3:20-ish., but I scored a nice 8 1/4 housing with 2:71 gears in it, (upgrading the stock 7 1/4 that has 2:93? ish..)

On an E.T. slip or seat of your pants feel, a stock converter with 3:21 gears
[vs]
a mild stall with 2:71 gears would be noticeably different? How so?

Would increased stall make up any difference going the 2:71 over the 3:21 ratio?

Thanks to all who weigh in on this.!!

What is the main use of the vehicle? Daily driver, cruiser, race car?? How much freeway driving are you going to do?
What size rear tire?

A mild stall to me would mean something no more than 22-2400 rpm.