Editing GM firing orders

{{copyright}}
==Overview==
Firing orders for GM engines.

==Chevrolet==
[[Image:Chevy_firing_orders.jpg]]

*When using a 4-7 swap camshaft in a Chevrolet Small or Big Block, the firing order will change to 1-8-7-3-6-5-4-2. 

*In the case of reverse rotation marine engines where the distributor rotation is opposite of a standard rotation engine, the reverse rotation firing order becomes '''1-2-7-5-6-3-4-8'''.

Be sure on the Chevy V8 that the #5 and #7 wires aren't accidentally transposed. They are next to each other in the firing order as well as at the cylinder head, so be careful.

[[File:Sbc fo.jpg]]

==Buick==
===Buick V8===
[[File:Buick v8 firing order.jpg|border]]
*The 1970 Buick 350 ci engine has a firing order of 1-8-4-3-6-5-7-2 and the rotor spins counterclockwise. The number 1 distributor cap terminal is at 5 o'clock viewed from in front of the car.
*1963-'66 401 and 425 ci Buick engines have a firing order 1-2-7-8-4-5-6-3 and the rotor spins clockwise. The number 1 distributor cap terminal is between 8 and 9 o'clock viewed from in front of the car.
*The 1964-'66 300 and 340 ci Buick engines have a firing order of 1-8-4-3-6-5-7-2 and the rotor spins clockwise. The number distributor cap terminal is at the 4 o'clock position viewed from in front of the car.

===Buick V6===
[[File:Buick V6 firing order2.jpg]]

==Oldsmobile==
[[File:Olds firing order.jpg|border|250px|]]

==Pontiac==
[[File:Pontiac firing order.jpg|border|260px|]]

==Cadillac==
===331, 365, and 390 V-8 1962-back===
[[File:Cad firing order 390 62-back.jpg|frame|left|1962-back 331, 365, and 390 ci with counterclockwise distributor rotation.]]
<br style="clear:both"/>
===390, and 429 ci 1963-up ===
*1-8-7-2-6-5-4-3 
*Clockwise rotation

===368, 425, 472, and 500 ci 1968-up ===
*1-5-6-3-4-2-7-8 
*Clockwise rotation
[[File:472.png]]

===4.1L and 4.5L===
[[File:Cad 4.1-4.3 L fo.jpg|frame|left|4.1 and 4.5 L]]
<br style="clear:both"/>

===Northstar=== 
*1-2-7-3-4-5-6-8



[[Category:Engine]]
[[Category:Firing orders]]
[[Category:GM]]
[[Category:Ignition]]