Disc breaks from....what???

Hey guys found a partial casting # on the knuckle
34028(XX) cannot read the last 2 digets
when I run the P/N on search this is what i get...sound correct to any one??

401401019 76-81 R,W,X,SR STEERING KNUCKLE ARM 3402848 SOP
or what is the p/n for the unicast knuckle..