Joseph,
If you and/or a male descendant of your mother's father can take the Y-Chromosomal DNA test with FTDNA, they will let you know if you/he has the "Cohen Modal Haplotype" (CMH), which is very common among Jews who traditionally believe they are Cohen/Priests.
See the paper: Y-Chromosomes of Jewish Priests and the site: Cohen project Y-DNA results.
