Personal Crisis in Western NC: HELP!!!

So I realized something today.

My speedometer is way way freakin off and I can accelerate at modern-car-speeds without having to hardly crack the throttle...

Anyone got any ideas on why this happened? The way she accelerates, I thought I had a 318 under the hood.

I coulda sworn that when I was turning the axle on the new rear, I counted 2-3/4 rotation on the pinion...

Now, I'm wondering if I actually miscounted and ended up with 3-3/4. :D