Lucky Lee - I did some deeper searches through various Chevy Master Parts Books on the front spindle (steering knuckle, Parts Group 6.020) you seek. According to what I found, there were actually 3 different GM Part Numbers and at least 2 different casting numbers assigned to them that fit the years 1941-1950 1/2 ton trucks. I see in zooming in on the article you posted above that the source indicates that 1941-59 truck spindles are the same, but since there isn't any spec's listed there for the truck spindles, like as shown for their passenger car data, I'd want to verify that before acquiring and trying to install 1951 and later spindles. IIRC, when the Bendix brakes where introduced for the 1/2 ton truck in 1951, there was a change to the backing plates and spindles, using larger bolt holes than the previous Huck brakes. Something to consider if you intend to keep Huck brakes on your truck.
1941-42 Chevy master Parts Book lists them as GM# 605141 (no casting number listed)
1944-54 Chevy Master Parts Books lists them as GM# 607306 (forged casting# 3664551)
1957-71 Chevy Master Parts Books lists them as GM# 3708866 (casting# 3708831)
Although the spindles were listed in the Parts Books up until the number was removed in 1971, they still are only listed as fitting 1941-50 1/2 tons.
I did a semi-quick stroll through the web and found no "spindles" or "steering knuckles" offered for sale that fit these years 1/2 ton models. You may need to expand the search to front axle assemblies to find a usable spindle, if there isn't a 'Bolter hanging on to one that would let it go.
Best of luck in your search.
