Differences between 351C and 351M??
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From: Still under the hood in O
Differences between 351C and 351M??
The two big differences I know of are the main journals - 2.75" on the 351C - 3.0" on the 351M.
And the heads. The 351C used a 4V head that are much larger than the 2V 351M/400. The 4V is good for upper RPM HP engines but not too good for low end torque (from what I hear anyway).
And the heads. The 351C used a 4V head that are much larger than the 2V 351M/400. The 4V is good for upper RPM HP engines but not too good for low end torque (from what I hear anyway).
Senior User
Joined: May 2003
Posts: 150
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From: San Diego
Differences between 351C and 351M??
the "M" also has a higher deck height like the 400.
As far as torque, it's true about the Cleveland.
I've never towed anything with mine, but it has no problem lighting up both back tires.
I used to hear all the time "the Cleveland is no good for nothing but racing". That's B.S.
mine works as good as it looks.
As far as torque, it's true about the Cleveland.
I've never towed anything with mine, but it has no problem lighting up both back tires.
I used to hear all the time "the Cleveland is no good for nothing but racing". That's B.S.
mine works as good as it looks.
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From: (near) Denver USA
Differences between 351C and 351M??
There was a recent discussion similar to this topic:
https://www.ford-trucks.com/forums/s...hreadid=148458
https://www.ford-trucks.com/forums/s...hreadid=148458
Laughing Gas
Joined: Sep 2013
Posts: 1,118
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From: North Idaho
The 351M and 400 are essentially tall deck Cleveland engines. Because of the taller deck, and larger main bearings, the rotating assemblies are different. Early versions of the 351M and 400 had 351C 2V style heads, while later versions had a water jacket all the way around the exhaust valve.
The 351C could be 2V open chamber heads, or 4V with open or closed chambers.
The 351C could be 2V open chamber heads, or 4V with open or closed chambers.
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Remember "2V" and "4V" means two barrel or four barrel carburetor, not 2 or 4 valves per cylinder.
As for brackets fitting, I would not count on it as the deck height is a little over an inch higher on the 351M. Parts from the 400 should interchange fairly freely with the 351M, and if you are in the same model year and vehicle type, they should match 100%.
On the backside of the motor, the 351C uses the SBF pattern as found on the 289/302/351W, as well as the 240/300 six. The 351M/400 use the "385" BBF pattern, as found on the 370/429/460. A very few early 400s had the SBF pattern.
351C: 1969 (for '70) to 1974. Cars and Rancheros only in the US, no trucks.
400: 1971 to 1982
351M: 1975 to 1982, simply a 400 with a 3.5" stroke. Crank and pistons differ to make the change.
As for brackets fitting, I would not count on it as the deck height is a little over an inch higher on the 351M. Parts from the 400 should interchange fairly freely with the 351M, and if you are in the same model year and vehicle type, they should match 100%.
On the backside of the motor, the 351C uses the SBF pattern as found on the 289/302/351W, as well as the 240/300 six. The 351M/400 use the "385" BBF pattern, as found on the 370/429/460. A very few early 400s had the SBF pattern.
351C: 1969 (for '70) to 1974. Cars and Rancheros only in the US, no trucks.
400: 1971 to 1982
351M: 1975 to 1982, simply a 400 with a 3.5" stroke. Crank and pistons differ to make the change.
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why don't new people read the stickys..... lots of info here
https://www.ford-trucks.com/forums/1...nd-tricks.html
https://www.ford-trucks.com/forums/1...nd-tricks.html
Cargo Master
Joined: Nov 2009
Posts: 2,364
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From: starship enterprise
351c used a smaller wrist pin as well, Mine had the same heads as a 400, pistons are different, crank different, different wrist pins. Can't say performance wise if there is anything amazing about the 351c as it appeared to me to be a 351m upper end (2 barrel carb and 2 barrel intake, same exact heads as 400/351m) but I believe it would have had more compression because the pistons had a much smaller dish to them. Bore and stroke appear to share that of 351m.
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