351 or 400

[Little Giant]

Ok while I was in Iraq I bought a 79 bronco to replace my 78. The body and frame was just to bad didn't want to dump that much money and time in to it. But my wife picked up the truck. So, he told her that it had the 400 in it but all the stickers say 351 what is the easiest way to tell which one it is.... on another note. I got my truck shipped from Texas to California. I pretty much stripped this truck down its ready to go to the junk yard. of course. I only have a couple of saved parts from the truck that were not trashed like the core support round head light covers grill. stuff that can be cleaned up and used.

 

[Crude dude]

Its the same externally. You will have to pull a head off and measure the stroke. Bore is the same for 351M and 400 too. 351M has a shorter stroke but taller compression height pistons than the 400. 351M is 3.5" stroke and 400 is 4.0" stroke.

 

[Krafty]

or find an Id tag on the motor and run the numbers and see what comes up. also verify with the vin what the bronco had from the factory.

 

[andre]

need to find engine casting no# and head casting no@ to

there more then on type of engine 351 w 351 c 351m 351m 400 cal also 400

may of swamp the head may not b original engine

also some have 5 1/2 spacing for small bell housing some 7 1/2 spacing

if sticker say's 351 m then it a 351 mod 400

here this may help

http://en.wikipedia.org/wiki/Ford_335_engine

 

[cantbecaught4]

I believe that the cranks should be stamped. You could look up the stamp number on the crank to know what model you have.

 

[Fritz180]

if you remove the starter, the engine number is right there I believe.

 

[fenris]

351 and 400 use the same block so you cant tell externerally. ive ben told to take off the head and measure the stroke. 351 is 3.5" and the 400 of coures is a 4.00"

 

[Dittliesquat]

Forget all that hard stuff. Here's a super easy way to tell if it's a 351m or 400.

Open hood (if one is present) look at distributor. Look to the right of distributor at the block. Specifically the timing chain protrusion section where the distributor goes into the iron. There will be a half inch wide rectangular rib extending from the face of the block out toward the water pump. If that rib only goes half way from the block to the water pump -351m- if it goes all the way to the absolute front of the block casting -400-.

See the block on the left of this page (one on the right is a 351clevland) that big rib indicates a 400. It'd be half as long if it was a 351m.

See, easy. An' lazy-likes-easy.

 

[BUCKIN'94WFO]

Forget all that hard stuff. Here's a super easy way to tell if it's a 351m or 400.

Open hood (if one is present) look at distributor. Look to the right of distributor at the block. Specifically the timing chain protrusion section where the distributor goes into the iron. There will be a half inch wide rectangular rib extending from the face of the block out toward the water pump. If that rib only goes half way from the block to the water pump -351m- if it goes all the way to the absolute front of the block casting -400-.

See the block on the left of this page (one on the right is a 351clevland) that big rib indicates a 400. It'd be half as long if it was a 351m.

See, easy. An' lazy-likes-easy.

WHAT?...I mean -

what? If I'm not mistaken, the question was NOT whether the motor is a "Cleveland" or "M"! It was whether the motor was in FACT a 400(M) or a 351(M), which in the case of missing or unseen block casting numbers, can ONLY be distinguished by the crank throw. Any 351 (M) block can be retrofitted with a 400(M) crank by changing out the rotating assembly as a whole. Meaning that the crank,dampener,rods AND pistons, from a 400(M) can be transplanted into a "run of the mill" 351M block and you'll never know the difference without checking the "stroke",as mentioned earlier on in this thread. I know, because that is what I have done with my 351M!If you know how, AND have all the gadgets, swept volume can be used to determine which crank is present....on second thought,never mind! If the motor is runnin' good, why does IT matter which crank IT has? Just a question

. After all- you can't take it back to the person you bought it from and MAKE 'em eat it!

Can you?

 
Now...I don't know Dittliesqaut.
BUT, I think what Dittliesqaut may have been TRYIN' to say, is that the deck height of the 351M/400M blocks is "taller" than the "Cleveland" block(on the right side of the picture) so it APPEARS to have a ?protrusion? out of the block. At least I think I know Dittliesqaut.. was tryin' to say that, or at least seemed to mean that!
And, as for the poster (Andre)that made the remark that Ford made several "351's", and proceeded to try and name 'em off, WHAT?.... I mean,what?

Again, I don't recall a question being raised about the bellhousing "bolt" spacing being involved, OR even wonderin' "which" 351 he had! I'm sorry. That statement just FURTHER confuses things. His question was whether or not he could "verify" that the truth was indeed told by the person who his wife bought the truck from!! By the way,on the "Cleveland" blocks AND it's "
Modified
" versions, the 351M and 400M, the water leaves the block through the upper passenger side of the block "ITSELF", and NOT through the intake manifold -as with the "Windsor" family of motors! Just sayin',.... in case Andre ever needs to clarify the differences between a "Cleveland" based block and a "Windsor" based block in the future

! Another "By the way"-Ford saw that they had a good thing in the canted valve heads of the "Cleveland"(335) family and THAT'S why we have the "Modified" versions of this motor. Ford wanted to make the block decks taller and wider so they could more easily mate them up to the C-6 Trannys, which went behind any motor bigger than a 351, installed in the truck lines! Well...

now I'M chasin' rabbits all over the place!

Peace out! WE should always remember to NOT sweat the petty stuff- and never pet the sweaty stuff!!