Personal Crisis in Western NC: HELP!!!

/6 Matt said

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

Click to expand...

Get a watch with seconds on it. Take your car on the highway and go a steady 60 mph as consistantly as you can without changing speed. Catch your seconds as you pass a mile marker, then see how many seconds it will take to get to the next mile marker. At 60 MPH it should be exactly 1 minute or 60 seconds. If it is not, accelerate or decelerate until you get to 60 seconds between mile markers, this will be your new 60 mph mark (unless you get a new spedo gear in the transmission to correct it).

Also take note on how many miles your speedo says between mile markers, that will also give an idea of how much different the new rear end gear is compared to your old one. If you need help converting, post up the numbers after you try this, and we can help you.