C10 Truck Parts

Hey guys. I am searching for parts off and on for my GMC 1/2ton truck. With the search engine filters on web sites they hardly ever have the C10 as an option for the GMC or even Chevy. They usually start with the C20. Back in the day I remember they had C10, C20, C30. I think the C10 was the 1/2ton, C20 was the 5/8ton, and the C30 was the 1ton. I always pick the Chevy options knowing they are probably the same. Do you think i will have any problems with selecting parts using the C20 option other then suspension maybe.:confused: