tire pressure

Does anyone know the recommended tire pressure for 87 Bonneville? The tire placard on driver's door is all washed out and unreadable. Not stated in owner's manual, Pontiac shop manual, or Chilton manual.

just had my TPMS replaced and had an interesting discussion with the mechanic they recommend not to use the max tire pressure, but something closer to 35 psi of course the TPMS thinks this is too low, in fact it thinks anything under 50 is too low (max is like 54?) so have idiot light...