Oldsmobile V8 Engines 1967 and later:
Rotation: Counter-clockwise
Firing Order: 1-8-4-3-6-5-7-2

Buick Engines for most except HEI:
Rotation: Clockwise
Firing Order: 1-8-4-3-6-5-7-2

the 1970 Buick 350 has a counter-clockwise rotation on the rotor and the number 1 tower at the 5 o'clock position while standing in front of the car.

63'-66' 401 & 425 ci Buick engines have a firing order 1-2-7-8-4-5-6-3 and rotor spins clockwise with number 1 tower between 8 and 9 o'clock positions.

The 64'-66' 300 and 340 ci Buick engines has the same firing order as Chevrolet but the number 1 tower is at the 4 o'clock position and the rotor spins clockwise.

Chevrolet / Chevy Engines:
Rotation: Clockwise
Firing Order: 1-8-4-3-6-5-7-2

Pontiac Engines for most 1955 through 1981:
Rotation: Counter-clockwise
Firing Order: 1-8-4-3-6-5-7-2
Note: the 307 Pontiac V8 engine rotates clockwise