69 z28 radiator core mounting

[canadair]

does anyone know of the correct bolts that hold the radiator to the core support did they use  rubber inserts with bronze nuts to hold the core to  the support or was that just for a/c cars

[JohnZ]

does anyone know of the correct bolts that hold the radiator to the core support did they use  rubber inserts with bronze nuts to hold the core to  the support or was that just for a/c cars

The radiator used two 5/16" bolts into pierce-nuts on the passenger side, and two #10 hex washer head machine screws into rubber Well-nuts on the driver's side.

[68Zproject]

This is the top one on a 68,  passenger side.