Paul - I recalled doing some research awhile back on the spindle you seek for another 'Bolter.
Here's some relevant info that should be helpful to you in finding another spindle:
The spindle (steering knuckle) that fits your '56 (1951-57) is GM# 3709756 (forged piece with casting# 3708831).* Same spindle used for both left and right sides. See this page from the 1929-57 Chevy Master Parts & Accessories Catalog:
http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0523.htm **
* NOTE: In the 1929-54 Catalog, their are a couple different GM#s for earlier versions of the spindle that are noted to fit '51-'53 (GM# 3696337) and '54 (GM# 3709756) steering knuckles for those 1/2 ton trucks, but from what I can tell the '51-'53 number was replaced by the GM# 3709756 listed in the 1929-57 Catalog. It is a "possibility" that you may stumble across someone offering one of the early numbered parts. If you do, it would work for your application as well as the newer numbered part GM# 3709756.
** NOTE: In the 1979 Chevy Master Parts & Accessories Catalog, GM# 3709756 is also listed for all
'51-'59 1/2 ton trucks. See this page:
http://www.gmpartswiki.com/getpage?pageid=22515With this info, you can widen your search of trucks to hopefully find another spindle. More likely than not, your best bet will be to find someone offering a complete front axle. With that, you get two spindles to chose from to use to replace yours.
I'll be back soon with some possible sources near you, if I can find them.
