You have the 4.75" bolt pattern. Its more or less the standard bolt pattern for GM. Lets put it this way. Everything that is RWD and NOT a full size car or truck used that bolt pattern including the 80's Z/28. The third gen Camaro with 16" wheels uses a different back space and you can only use the front wheels. You may have a rub problem if you use the rears with out a spacer. 2WD S-10's used the same 4.75" bolt pattern too.