351M/400 are small blocks?

 

Yes they are

http://www.oemfordparts.com/faq/smal...v8.htm#351M%20(MOUNTED)%20AND%20400

 

Ok... I read that it says that they are both 400 blocks but it has 429/460 bell housing design..... And everyone of the Ford dealership mechanics I talked to said the 351M and 400 are big blocks. So, if they are both small blocks and the Windsor is a small block, why will none of the parts interchange?

 

Because they are from different engine families.

The Jury is still out on the *displacement of engine relation* to being considered a small block/big block by small people.

In the FE series engines the 390 is considered a big block whereas a 352 (Same block) isn't.

All the books I own, have determined that the 351M/400 engines are considered a small blocks.

There is another thread about this from last year, I'll try to find.

Until I do, have a look at how these engines are split up from these books.

http://www.motorhaven.com/customer/home.php?cat=44

 

Some of the "small block" parts DO interchange. You can bolt the heads from a 400 on a windsor and with a "few" mods make what is called a Clevor. The 351M/400 shares the same bore spacing as the 289/302/351W and 351C engines.

Small block and big block are Cheby terms that have no meaning with Fords.

Ford has engine "Families".

Engine bell housing pattern "sizes" are largely determined by the output torque of the motors and the size of clutch or converter that must be used.

 

There isn't any need for any jury or any debating. Ford never has printed nor issued engine data, specs or repair manuals that use "Small block" or "Big block" terms. Those terms originated from the brand X car manufacturers and have somehow bled over into use in describing Ford engines.

Here is the problem in using brand X terms on Ford engines:
Is a Y block a small block? Where do the Flatheads fit in? Are Modulars small blocks too?

I have no trouble having a conversation with a well seasoned Ford person without stumbling over the big block small block issue because it has never been part of Ford engine families and plenty of people incuding me understand that very well. I know the engine families and have no intentions of trying to simplfy the Ford engine family terms into two groups.

If you use the Ford engine designations like 289, 302, 351W, 351C, 351M, 352 FE, 360 FE, 390 FE, 428 FE, 400, 429, 460, etc... you will find that they are destinguishable from each other using the cubic inches and the letters when needed like for a 351. Knowing this, why do you need terms like big block or small block? If the only thing that comes to mind is horsepower and torque and the bell housing bolt pattern then you haven't simplified anything and most of the time a parts store still won't know what engine you are dealing with unless you use the Ford terms.

Go to a parts store and try to purchase engine parts for a 351 small block and you are not going to get what you need if it is a 351C or 351M. You are most likely to get 351W parts. I have witnessed this.

To me the differences are as clear as the terms for carburetors verses the terms for fuel injection.

 

Good post, and I totally agree, now, where does the jury stand on what the FE designates ? Ive even heard it meant Ford/Edsel

 

In fact FE does stand for Ford/Edsel.

 

Oh No.....

We're not going to do another never-ending thread on this subject

 

Thanks Dennis!