as a general rule divide pinion into ring gear.

a 10- 44 gear count would be a 440 to 1 ratio . are you sure on the ring gear tooth count ,my books do not show that ratio .there is a 410 to 1 ie 10- 41 ratio listed for the 20 and 30 series trucks.the tooth count should be on rinr gear by the part number.there are a lot of aftermarket gaers around ,i had a set of 5.13s in a 57 chevy car one time.if part # is ongear will gladly resurch for you.