No factory overdrive for that specific truck. How ever an E4OD from a later 460 will bolt to the M engine. Would need an aftermarket controller and fabricate mounts for the transmission.
Firing order is : 1 3 7 2 6 5 4 8
if it is the stock engine then it is not a 351m because ford had stopped making the engine before 79
of course.
For a 351m engine the oil sending unit is located on the top of the engine between the carburetor and the firewall.
the 351M/400M Ford motor has the big block bellhousing bolt pattern, like the 460 and 429 engines. So any overdrive transmission would need to have the Ford Big Block bolt pattern or you will need an adaptor. I do not believe Ford built any overdrive transmission for the Big Blocks. So I don't think there are any direct bolt ons The Ford AOD is a Ford Overdrive transmission that may be used but an adaptor plate and other modifications will have to be made. The GM 700R4 is a good overdrive transmission but would definitely require an adaptor plate.
not very much
Engine oil capacity, 5 qts with filter change.
need to know the spark plug gap for a 1979 Mercury Grand Marquis with 351 modified.
1-3-7-2-6-5-4-8
No, a 7.3 transmission will not bolt directly to a 351M big block. The 7.3-liter engine typically uses a different bellhousing pattern than the 351M, which means you would need an adapter or a different transmission designed for the 351M to make the connection. Additionally, other factors such as the torque converter and transmission mount compatibility may also need to be considered.
Google search - 351M vacuum diagram
No, the 351m and 400 do not take the same crank. The 351m (part of the 335 engine family) has a different crankshaft design compared to the 400, which is also part of the same family but has a larger stroke and different specifications. While they share some components, their crankshafts are not interchangeable due to these differences in design and dimensions.