['68OrangeSunshine]

1157 is the bulb type for the Turn signal/Tail light/Brake lights and Parking light in rear, and Turn signals in the front. Check all those. Check the contacts, and see they're in proper orientation. Look behind the back bumper for the wiring bundle to see if some PO didn't hack the harness for trailer connections.
1967s are different from 68-72s, in that the front amber lights are Parking lights, that go on with the first click in the Headlamp switch, and go out when the headlights come up on the 2nd click. They do function as turn signal indicators, however. [And 4-way flashers]. And you have no side markers -- not even reflectors. Also '67 normal.
You may have to pull the steering wheel and R&R the Turn Signal Switch. I had some screwy rear tail light/turn signal gripes on my '67 K/10 Suburban that were cured when I replaced the T/S Sw.