Time can be rough on your axles, especially for a 4WD. Years of use and abuse can cause damage to the splines of bearing surfaces. Hurst Engineering axles are made from 1541H alloy for strength and durability. Our replacement axles for 1970-1981 K trucks with a 8.875 12-Bolt feature 30 splines, 6 x5.5" lug pattern and are 31 7/16" long. Look to Hurst Engineering for your truck axle needs. Sold individually.