1 - 3 - 7 - 2 - 6 - 5 - 4 - 8
The distributor rotor turns COUNTERCLOCKWISE
The marked # 1 position on the distributor cap faces to the REAR and slightly towards the drivers side
The engine cylinder / spark plug locations are numbered :
firewall
4 - 8
3 - 7
2 - 6
1 - 5
front
1-3-7-2-6-5-4-8
Firing order is : 1 3 7 2 6 5 4 8
Google search - 351M vacuum diagram
http://boxwrench.net/specs/ford_351C.htm
351w,351m,wiring and distribution fireing order=1-3-7-2-6-5-4-8
The firing order for a 351M Ford engine is 1-3-7-2-6-5-4-8. This is typical for many Ford engines with a similar design. The cylinders are numbered from the front of the engine, with the driver's side being 1, 3, 5, and 7, and the passenger's side being 2, 4, 6, and 8. Proper adherence to this firing order is crucial for optimal engine performance.
351W (5.8L), 351M, 400 and 1994 and later 5.0L V8 Engines... 1-3-7-2-6-5-4-8
of course.
need to know the spark plug gap for a 1979 Mercury Grand Marquis with 351 modified.
if it is the stock engine then it is not a 351m because ford had stopped making the engine before 79
Counter-clockwise 1-5-4-2-6-3-7-8 Number 1 plug is located passenger side front. If this is not the OEM engine or the cam has been changed then this firing order does not apply and it may be Ford (5.0L HO, 351W, 351M, 351C, 400): Counter-clockwise 1-3-7-2-6-5-4-8
Yes. basically the 351m is a Cleveland with a modified deck height.