Hey Folks,
I've heard a few people refer to the 351M engine as a Big Block Ford engine...Should a 5.8 liter engine be considered a Big Block??? (personally don't think it's a big block) If I'm not mistaken the 351M has a Big Block bellhousing bolt pattern...Just looking to know the facts next time someone mentions they have a Big Block 351M.

Ron

 

Yes, it is in fact a big block..... If you were to measure it you would find that the 351 cleveland (M/400/C) motors have a "big bock stance" (width across the top from the outer sides)

 

By that same logic, a 332 isn't a big block, either. Or is it? IMO, displacement has very little to do with whether it's a BB or SB. The 351m/400 is an altered 335 family engine, designed to fit where a BB would also fit. IIRC, the 351m/400 use the same perches as the 460, too. It's a small block in a big block kinda world.

 

The 351M/400 block is virtually the same height as a 429/460 block and has the same bellhousing bolt pattern. However the bore spacing is the same as a 351W/C and the heads will interchange. So call it whatever you want but remember that the terms "Big Block" and "Small Block" were coined to describe Chevy engines...

 

Big Block Small Block La la la la .. lets kick this horses to death again ..

It's not how big the engine looks on the top or how far the heads are apart from each other or which bellhousing bolt pattern it uses to determine which block size it is .
It's the Bore Spacing that determines wheather it's a big Block or small block..... Which by they way is a "Chevy" Term because they only have the two size V8's engines..
Ford Has many differant V8's engines which if you look through the forums here you'll see .
221/260/289/302/351w V8
4.6/5.4L Modular V8
351M/400/351 Cleveland
Y-Block V8 (272, 292, 312, 317, 341, 368)
FE V8 (332/352/360/390/406/410/427/428)
385 Series - 370/385/429/460

 

big block and small block are cheby terms (along with posi we use trac-locs)please stop calling my genuine ford a cheby for i don't like it
but applying cheby terms to ford(don't work persicly) it would be considered a small block that will crack a 351 wheezer's az pullin but the later would be fine for cars or a low sport truck/ranger where upper end is more important than low end thumper stump pullin shaft breaking power in a lighter, slightly more compact box than a 460 or FE

still would put simularly set up or down(ie. stock) 400 up against a 460 think 60 less cubes and much less weight. de-turn a 460 or tune a 400 and we will see. one problem i can't bring myself to hook to another ford but i know a guy with a suburban what do ya think...got to finish my build before i try..um do it

 

Help me out here.

1. Is the 400 a small block or a big block? (it's a medium block)
2. What does the "M" stand for on a 351M engine?
3. Should I run an external oil line to the rear of the block?
4. Did the 400 ever come with a 4 barrel manifold?
5. How much compression will my engine have if I buy some Aussie heads?
6.
7.
8.
9.
10.

 

Brain S. don't forget these ..

What mods can I use in this 400 Smog motor
Can I stroke a 400 ?
how much power can I get from my 400 if ?
Where can I find Flat top Pistons for my 400
Which pistons can I use in my 400 buildup ?

 

How come you spent so much money on a 400, when you can make more power with a 460 for half the price?

 

you guys didnt look at this logicly. since peole want to claim that that the block is a "big" block, thas fine. but the heads fit on a "small" block. those ford guys are real good.

 

Well a 460 is easy to do ..everyone has one .. anyone can open a catalog and order parts to make it go fast .
It take a little home work to do a 400..and as We all know you can't open a catalog and just order go fast parts for the 400 now Can we ....

When it's all done you have something nobody else really has.

That's Why..........................

 

Yea its like saying i have a Chevy Pickup...with a 350.....you see that around everywhere.

 

It's also rewarding to put the know it alls in their place. Those who can't think outside the box. We have to look a little farther than the local 7-11 for parts. We can't just copy what someone else did.

"When it's all done you have something nobody else really has."

That's part of the reason behind my motors. There are probably 25 finished or "works in progress" of the Mad Max replicas in the US and Australia. Not one has a funtional blower, let alone a part time blower. If I decide to go with the Arao heads, I will probably have 15K in the motor but it should be the Ultimate of the Last of the V8s.

 

Originally, on the 351M, the "M" did not stand for modified or anything for that matter. (though even FoMoCo refers to the engine family as "modified" now days) the M was the letter half- way between C & W. (351C - 351W) the 400 originally never had a letter designation, as Ford only built one engine with a displacement of 400 CID. And like everyone else is saying, the 335 family of engines is neither a small or big block, as that is a Chevy term.

 

I agree, big block and small block are GM terms, however I always have discerned the two by the main bearings. Deck height, bore spacing, trans configurations will change within engine families, hence a poor way to categorize. It seems to be consistant that those engines where the main caps are exposed below the bottom of the block are small blocks and those webbed up inside the block are big blocks. The 335 series caps are exposed. To me, its a small block if you wish to use those terms.