1954 C-1-B axle ratio

[WPVT]

I have a 1954 C-1-B truck that is new to me. Starting off, first gear seems more like second. The previous owner says that the rear axle was replaced at some point, so my fear is that they used an incorrect replacement with a different ratio than original. 

What should the original differential ratio be for this truck with a 3 speed transmission ? I am planning on spinning the driveshaft with the wheels jacked up to compute what I have now. 

[59bisquik]

Most likely it was a 4.10. There was a lower gear set like a 4.89 or something that is a little more rare if memory serves.  Do you have a pic of the rear axle? Is it a stock housing with different gears or a whole different axle? The stock housing can have different gears swapped in from other Mopars of that era. I put 3.73's in mine out of a 54 Plymouth.