I worked at a Camaro Parts business 1983-1997. We had boxes full of NOS GM tie rod ends, sleeves, idler arms, ball joints, bought out of Chevy dealers. As we got into restoring our '67 Z/28 and COPO projects, imagine my surprise when most of the NOS was not an exact match for the original assembly line parts on the cars.
Obviously GM had several sources for this stuff. Wouldn't worry about it.