American Top 40 in the Boston market

[Matthew Osborne]

This weekend something popped into my mind from the past that never made much sense to me.  Maybe someone on this list might have some more insight into it...In the Boston market, the show 'American Top 40 with Casey Kasem' used to run on WBZ 1030 from 1985 until sometime around 1991.  Why in the world did this run here and not on Kiss 108 or even WZOU during this time period?  Did Sunny Joe White and/or whoever programmed WZOU at the time not care for the show?  Everywhere else I came across the show during this time, it was on a CHR FM station except for Boston.
If anyone has any inside knowledge on why this was please share.
Matthew OsborneWest Sand Lake, NY