Don't worry derf your not mad! Makes sense.
Ability to get power into the ground and therefore the power back is the most important thing in sprinting. Being efficient at it separates the good from the great.
You have easily increased your ability to produce force against a resistance with your impressive strength gains.
I wonder how your 1km would go now?
3 minutes is fairly good! I remember my brother as a decent runner trying to break 10 minutes for our just over 3km block. Think his best 400 is 50 or 51, pretty sure he never broke the 50 mark.
I'll be asking him this weekend.