TorqueFlite Burnouts

So, if I'm driving a 727 with a shift kit, stock vavle Bobby, on the street, dont downshift to 1st gear ever? 74 duster , around 400 ho 340, 2200 stall, 4:10.
Apples and oranges. I don't drive on the street and I was assuming manual valve body, which I shouldn't have done. Who is Bobby?