76 only needs tail pipe test.
76 is eligible for collector's plates. I have never seen or heard of (until Ken's post) anything but the 5 year variety. Unless they change the laws, once you get the collector plates you never have to be tested again, only exception is whenever a vehicle changes hands (or moves here from out of the AIR program area).
The only equipment you MUST have is smog pump - it must be hooked up and appear to be functioning, whether it is or not. Nothing else is required. Yes they will check for unleaded sized filler and cat, but that was not introduced until the 1979 model year, so it doesn't apply to a 76.
All the other suggestions apply: Fresh oil change, new air filter element, new plugs, set timing to factory 7° BTDC, increase idle speed some. Do not be tempted to lean out the idle mixture: that will produce "lean miss" and fail you. You should be able to get away with it under the numbers with sea level jetting, I did for decades in my 76. Good luck!