I was told by my local CSK Parts Store, that you can tell the difference between 351M and 351C by the 3/4" sized number stamped on the front of the head, located just by the edge of the valve cover. I was told M= Modified 2= Clevland and 4= Winsor. Mine is stamped with a 2 on both heads. . . Is this the right info? If not, does it matter when buying parts? Help me oh wise Ford guys!!

 

I have never heard of this way of ID'ing between the 351 series motors. As for parts interchangability, some parts swap between the C and M, it just depends what you need. One sure way to tell between the C and M is the M has the big block bolt pattern for the trans, C has small block pattern.

Nathan

 

I don't know if you got my other message, but being new at the Mechanic game. . . what's the difference between big and small block bolt patterns Nathan?

 

The 351m/400 have a higher deck height than the 351C. There is a ledge running behind the distributor. on the Cleveland its only about 3/8ths of an inch high. On the other motors it's closer to 1/2inch. Heads are interchangable.

1977 Ford F-100
400m/c6
280,000 miles
Stock on the outside
modified/rebuilt everything

 

[font size="1" color="#FF0000"]LAST EDITED ON 25-Apr-01 AT 11:00 AM (EST)[/font][p]>I was told M= Modified
>2= Clevland and 4= Winsor.
>Mine is stamped with a
>2 on both heads. .
>. Is this the
>right info?

white bread,

The info you gave is not quite correct. The 2 or 4 identifies a 351C head. All 351C 2V heads have the 2 cast into the upper corners of the heads. All 351C 4V heads have the 4 cast into the corner of the heads.

All M-block (351M/400) heads from the Cleveland Foundry (CF casting mark under the valve cover) have M cast into the upper corners. Some (if not all) M-block heads cast at the Michigan Casting Center (MCC casting mark) have no mark cast into the upper corners of the head.

Since all 351C and M-block heads are mechanically interchangeable on all 335 series (351C, 351M, and 400) engine blocks, the head ID alone does not identify the engine.

To the untrained eye, the easiest way to identify the engine is to find the block casting number on the lower right side of the block (just above where the starter mounts). 351C block casting numbers are D0AE and D2AE. M-block (351M/400) casting numbers are D1AE, D3AE, D4AE, D5AE, D7TE, and D8AE. If it is an original truck engine, the casting number is D7TE.

The 351M and 400 use the same blocks, so unfortunately, the only way to distinguish the 351M from the 400 is to drop the oil pan and identify the crankshaft by its casting number on the first throw or first counterweight (toward the front of the engine). 351M crankshaft casting numbers are 1K and 1KA. 400 crankshaft casting numbers are 5M, 5MA, and 5MAB.

>If not,
>does it matter when buying
>parts? Help me oh
>wise Ford guys!!

It depends on the part, as many are interchangeable between the 351C and M-block. For more info, check out the M-block tech article at:
https://www.ford-trucks.com/articles/mblock.html

BubbaF250

1980 F250 4x4 Custom, 351M/NP435/NP208/D44HD-TTB/D60-FF/3.55s 6750 GVW, Rust & White.

 

That's good info on the head castings. There are some subtle differences in the 2v heads. However on the block casting numbers I don't follow you. D= 197?, D0 though D9 = 1970 through 1979. It has no connection to anything else except the manufacturing year. IMHO

1977 Ford F-100
400m/c6
280,000 miles
Stock on the outside
modified/rebuilt everything

 

>However on the block casting
>numbers I don't follow you.
>D= 197?, D0 though D9 = 1970
>through 1979. It has no
>connection to anything else
>except the manufacturing year.
>IMHO

beartracks,

The first four characters in Ford part numbers identify the unique (original designed) application for the part. The middle segment of the part number identifies what the part is. All engine blocks are part number 6010, all cylinder heads are part number 6049, etc. Revisions to an original design are identified by a suffix following the basic part number.

In the case of engine blocks, the first four characters (e.g., D0AE) or a combination of the first four characters and the suffix (e.g., D0AE-J) identify the specific engine block design. In general, no two different engine blocks have the same first four characters and suffix. (I say in general, because there were some 351C engines that used the same basic block casting for both 4-bolt mains and 2-bolt mains, and in that case, the casting ID number alone does not differentiate between the two different engines.)

Since all engine blocks use the 6010 part number, and that number is not a unique identifier among engine blocks, the part number is typically omitted from the casting ID number on the engine block.

Therefore, the four character codes I gave are sufficient to identify an engine as either a 351C or an M-block (351M/400).

BubbaF250

 

>That's good info on the head
>castings. There are some subtle
>differences in the 2v heads.

Which "subtle differences" would those be?

 

re.2v heads. The best heads are probably the early Clevelands. I have seen head (Ms) with a raised boss for air injection in the exhaust port. This was never used and can be ground off when porting. I have seen other heads (don't remember origin) that have a noticably higher floor under the exhaust valve guide boss. This also would probably be for emmissions and appears very restrictive and probably cannot be cleaned up when porting. I believe all should have between 78 and 82cc of chamber volume as a factory spec. Some of these heads may contain single grove valve stems instead of the 4 grove style (for the retainers). As for the part numbers I would site as an example the famous and now rather rare 429/460 "DOVE" heads. The first two numbers indicate the decade and year, 1960, and the VE the engine family (I think). Also the 351m/400 are considered part of the Cleaveland family which might complicate things in terms of part numbers. It's a good opportunity to relearn some things. I need to look back in my records.

Bear Tracks
1977 Ford F-100
400m/c6
280,000 miles
Stock on the outside
modified/rebuilt everything

 

I have a set of 74 Cleveland 2V heads on the 400 I built and it had the "bumps" in the exhaust ports which succumbed to my die grinder and carbide bits quite nicely.

The "V" stands for Lincoln and the "E" stands for engine. All 385 series were designated as "V" because the engine was originally designed for Lincolns. The "T" in D7TE stands for truck

 

I knew that "T" in the part number had to mean TRUCK!

1977 Ford F-100
400m/c6
280,000 miles
Stock on the outside
modified/rebuilt everything

 

>As for the part numbers I would site
>as an example the famous and now
>rather rare 429/460 "DOVE" heads.
>The first two numbers indicate the
>decade and year, 1960, and the VE
>the engine family (I think).

beartracks,

As Bill mentioned, the "V" means Lincoln, which in the part number refers to the fact that the 460 engines were originally designed for the Lincoln car line. The fourth character (E in this case) refers to the engineering design group that released the part to production (Engine in this case).

As I said previously, the four-character combination (D0AE, D0VE, D7TE, etc.) in the block casting ID number always identifies a specific engine block design. That code alone is sufficient to distinguish any M-block (315M/400) from any 351C because they were different block designs.

In the case of the 351M and 400, as well as the 351C variants I mentioned previously (and even some 429s and 460s), the same block casting ID number could be used for more than one finished engine. In that event, you would need to look at some other engine component(s) to determine the actual engine type.

When it comes to other cast parts (i.e., cylinder heads, and intake and exhaust manifolds), the 3rd character application code is not as conclusive, as engines were often used in vehicles for which they were not originally designed, and for which application-specific components were developed after the original engine block design. For example, some 400 intake manifolds have the casting ID number D2SE (Thunderbird application), some 351C intake manifolds have the casting ID number D1ZE (Mustang application), and some 429 intake manifolds have the casting ID number D0OE (Torino application).

Bill,

Although most 385 series blocks are "V" blocks, there was also a D0SE 429 block (Thunderbird), and later a D5TE 460 truck block. I think after 1982, when 460s returned to more regular truck production (the year all M-blocks were discontinued), there were also some ExTE 460 truck blocks.

The use of non-"V" codes among other cast components is more common, as the 429 had some intake and exhaust manifolds that were not shared with the 460. These parts are fairly rare as the 429 was produced for only 6 years ('68-'73), and in most applications, it shared the 460 components.

BubbaF250

 

Boy, the Chevy guys really have it easy with parts interchanges don't they? Oh well, anybody can build one of "those".

1977 Ford F-100
400m/c6
280,000 miles
Stock on the outside
modified/rebuilt everything

 

>Bill,
>
>Although most 385 series blocks are
>"V" blocks, there was also
>a D0SE 429 block (Thunderbird),
>and later a D5TE 460
>truck block. I think after
>1982, when 460s returned to
>more regular truck production (the
>year all M-blocks were discontinued),
>there were also some ExTE
>460 truck blocks.

Good to know Dave, thanks.