Just to fuel the fire, there is no such engine as a 400m.....only a 351m, the 400 is a cleveland.....Or so I am told.....lol....bring on the responses, anyones info will be ponderer....

 

In regards too the 400M being a cleveland _No its not. Years ago I was sold a 79 bronco with a 351 "cleveland". Man, did I have a hard time getting parts for it. It seems alot of people think the m motor is the cleveland but its a totally different beast. Not sure the exact years but the 351C was a performance motor with a "small block bolt pattern that was put in muscle cars up to '72? The 351M/400 series were far from performance motors (late 70's emissions) and had a big block (as in 429/460) bolt pattern, but still a totally different beast.

 

Gee, Chad, sounds like you are just a big ol' troublemaker! Actually, you can call a 400 a "M" moreso than a Cleveland. Heads are just about the only interchangable parts between a "M" and a "C". As for the 351M and 400, the only significant differance is the crank and pistons. There is a tech artical on this site that maps the interchange between these three motors. So with this in mind, if I had to term the 400, it would be "M", but as is usually written "351M-400", I just call them "400".

Nathan

 

I have no idea where you get your information from. A 351m and 400m are the same block. The 400m is just bored and stroked differently. Most of the parts are interchangable but the pistons are not. Both the 400m and 351m are a medium block size... between a big and small block but closer to big and they will mount up to a big block transmission that is not from the FE family. The 351c is a small block. It is a totally different size. Take a look at both and see for yourself. I have a 1978 F-250 with a 400 and it sayes 400m stamped right on the block and the emmisions sticker also says 400m. Both the 351m and 400m were in trucks from 1977-1980.

That is all!

 

The motors are bored the same just different a stroke. The 351M has a 4,00" bore and a 3,50" sroke. The 400 has a 4,00" bore and a 4,00" stroke.

 

I was once in the dark like you,
Ford NEVER made a 400m.......I will
not pusue the issue of trying to
convince you otherwise.....I just
wanted everyone to know that there
is no such engine, the 400 is a
cleveland, not a 351c, a
400c....The tag on your engine has
a smudge on it, it says 351m/400, i
guarentee it...chec it again...who
cares anyway, get a real beast, a
460.....THAT is all....

 

Musta found out you guys were wrong,huh...no responses from ya......

 

No, we are just tired of arguing the point. There is more important fish to fry. The 3 motors are related in many ways and have many interchangable parts. If you want to call a 400 a cleveland, you do so. If you want to call it an "M", go ahead. A 400 is a 400 no matter how you classify it. If you have any valuable information about Ford trucks and motors, please partisipate. If you just want to argue about trivial jargon, please dont waste our time. Thank you and good truckin!

Nathan

 

Wrong I was sick of hearing you argue about this Chad. I have NO idea who keeps lying to you about the class, but I called Ford Motor customer service and talked with the tech department about it. It is in the same family as the 351m but it is not always called m. It is a totally newer block than the Cleveland which was made in Cleveland and the m was not. Most of these engines were made in Canada. It is NOT the same as the Cleveland, if you would just look at the 2 engines you could see for yourself. Also, read the Chiltons Truck manuel for Ford F-series 1976-1986 and it will explain the difference. Also note that the 351m and 400 are shown in the same diagram with the same parts because they are built the same. Who the hell keeps tellin you otherwise?

Jack T.

 

I worked for Ford from 1975-1982 as a mechanic. Jack is correct. While the 400 might not be "M" it is much closer to the 351M than any other motor. It is newer than the c and is a different size and bolt pattern. Same one as the 351m. Jack was right... he told ya.

 

The new petersons has some info on the 400 too, they say its a 400m....They are wrong also, there never was a 400m produced by ford.....

 

the Ford 400 is just that, a 400, no C, no M , no W , no X, no nothing, just a 400

 

Thats what i shoulda said fisrt, there IS no 400m, just a 400....

 

I've looked over all the posts so far and looks like lots of confusion so I'lls et ya'All straight in 1971 Ford produced the second engien int he 335 Series the 400 and gave it a C designation as it was derived as a BIG 351C motor had a 9:1 comp ratio and a decent cam in 1972 the motor lost compression down to 8.4 and got a retarded handicapped Camshaft and lost the C designation (this is backed up by the American V8 Histroy book as well as employees who work at Ford Proving Grounds) the C designation is not well knows beause it was held for such a short period of time. interchangealbe parts between the 2 are just about anythign on the bottom end top end is heads/exhuast componenets the 351C crank has different journals then the 351M/400 does but you can use a 400 crank in a 351C if you turn the journals down. As well as 351C pistons in a 400 if you open up the wrist pin hole just a tad. the 351M has unique pistons (carries the M designation as it is a "Modified 400 and came out in 74) and can not be used in any other engine. But basically I'd have to agree with Rick it's just a plane ol 400 No M deignation has EVER been placed on it.

 

Chad, ya keeps postin stuff on here claimin magazines are wrong an other stuff! What is your deal here? The 400 may not be an "m" but it is NOT a Cleveland like you said at first. Ya keeps changin ya story! Get it staight! Also, ya never saids why it is more like a "C" an less like an "m", what is ya resons?

It is usually catagoriesed with the 351m. Look in JC Whitneys or other parts stuff, get it straight.

Whats the deal here anyway?