Difference between K5 and K10 Blazer

[franken]

I've never heard of a 4x4 Blazer referred to as anything other than a K5.

C=2wd
K=4wd
10=1000lb load capacity
20=1500lb
30=2000lb
5=no one really ever discussed it.
We could theorize that a short bed truck should/could/might be a 5 but pretty sure they all came as 10s. Were spring rates different? Who can say? Try looking at parts store spring replacements (if listed) and see if Blazer and K10 are the same.