I was able to find out from my mother that John is buried at Mt. Olivet Cemetery. Here's his info, I checked it out on their website myself:

MT. OLIVET CEMETERY
17100 Van Dyke
Detroit, MI 48234-3975

JOHN IGNACZYNSKI
Date of Death: MAY 30, 1960 Cemetery:
Mt. Olivet Cemetery Location: Section M, Tier 5, Space 810