Depends on which starter.
Starters were installed on the engine dress line at Norwood (or LA), and if we're talking about a common starter, like the one used on the LF7 and Powerglide, then it would probably be dated very close to the car's build date. However, if we're talking about an uncommon starter, like the Z28, it could be up to a few months prior to the car's build date.
Going by your signature, you have a 6 cylinder 67 Camaro, and since the 6 cylinder engines only accounted for (approx) 26 percent of sales that year, a 2 month spread probably wouldn't be that abnormal.
Ed