Duramax swap - Rear axle gear in c10?

[bigmoe]

Originally Posted by 2mas

Hi,
I'm doing a Duramax swap into my 65 c10.
Now I need to program the ECM to get the speedometer to show the right values.
I've been looking at old threads on gears. My 65 C10 had a V8 auto. Do you know what gear it has in the rear end?

I can read HA0415W on the axle, but I cannot find anything on it.
When turning the drive shaft 2 revolutions the wheel rotates almost one turn (one wheel in the air)

/Thomas

Spin the wheel around TWO times and count the driveshaft revolutions.