It's less about the year than it is about the condition. As the engine wears you'll need a heavier grade oil (higher numbers). If the engine is new and the bearings are in good condition use an oil with lower numbers (5W15 or 10W30) and when the engine gets a little "tired) start using heavier grade oils such as 10W40 or even 15W50.
The rule of thumb is, watch the oil gauge. If the gauge starts going down too low or if the oil pressure light starts coming on when the engine is at an idle, switch to a heavier grade oil.
1977-80 Olds 350
According to alldata the recommend grade of oil is 5w30.
any 5w30 but would recommend a synthetic 5w30
There should be a cap on the top of 1 of the valve covers, remove it and put oil in there.
20/50
10w30 should work fine. Go to a heavier oil to increase oil pressure.
Toyota 5W30.
A 10W-30 or 10W-40 should be fine.
On this engine I recommend you use an AC/Delco filter.
its 0w30 fullysynthetic .you could use a better oil grade if you want .mercedes recommend mobil 1
Points, condenser, cap, rotor, plugs, wires, air, fuel, and oil filters.
Multi viscosity if you are in a colder clime, if not straight 30. It's better to go with a heavier oil on older engines for better sealing.