Does the 1987 Ford Thunderbird coup 5.0L V8 have factory forged pistons like a Mustang?

No, the 1987 Ford Thunderbird 5.0L V8 did not have factory forged pistons. While the Mustang GT of that era *sometimes* had forged pistons (depending on the year and specific build), the Thunderbird's 5.0L typically used cast pistons.