correct tire pressure? (placard unreadable)

I can't find the info anywhere I even downloaded an owners manual from: http://www.autousermanual.com/view/gmc/suburban/1994/a/owners-manual/ I hate to say it but maybe a dealer could help you out.

correct tire pressure for that veh with that size tire is 35 psi

dont follolw the truck specs on tire pressure because what the truck says may be different from the actual tire specks. look near the bead of the tire slose to the rim near where you found the tire size for the proper inflation for that specific tire