I recently acquired a 1978 f-150 with a 351 big block. Im not sure if its a cleveland or modified. Whats the easiest way to tell the difference? I also want to check and adjust the timing. Can anyone tell me what the timing should be set at? Also what size carb did they come with?

Thanks for the info! Im new to the 351 big blocks!

 

in '78 the 351s were 351M. now if it's not an M it could be a C or a W; but most likely it's an M. the 351M came with a 2 barrel carb. and if it's a C or W in the truck then the motor has been swapped. sorry I can't help you on the timing.

 

oh and by the way on this site we don't say "big block/small block" (according to some people) that's a chevy thing. we either call it by the series or name the exact engine.

for example: 351W doesn't have a series so you would just say 351W, but 351 C and M are in the 335 series.

I hope you can get the information that you need either from me or other FTE members. good luck

and I see that you are fairly new to FTE so welcome!!!

 

Thanks. Its the original engine as far as I know. It has an edelbrock intake and a holley double pumper on it. Not sure what size. Whats the easiest way to tell if its a M or C? Sorry for the chevy reference. Just used to most people considering the windsor engines as small blocks and the C and M as big blocks. Thanks for the welcome!


Curtis
Smokin Performance
96 PSD Too many performance upgrades to list!
88 Bronco Project Truck
78 F-150 New to the Family

 

phfff...Big/small block sounds a heck of a lot better than 335 Series 351 lol.

Cleveland and Modified are considered big blocks. Windsor considered a small block.

You will have a 351 Modified in your truck if it was not swapped. The Cleveland was not an option.

The 351 Modified used parts from both the Cleveland and Windsor, and in my opinion is not a very good engine. Hopefully the previous owner swapped out for a Cleveland, but I'm doubtful.

 

Are you serious? That post contains absolutely nothing factual. First of all, cleveland style engines(includes 351m and 400) and windsor style engines(260,289,302,351W) are all considered small blocks here on planet earth. Secondly, the 351m(a cleveland style engine, 335 series) shares absolutely zero parts with the windsor engines. About the only thing they have in common is bore spacing. It is possible to interchange components from these two families if you have some knowledge, but they are two totally different engines from the factory, and they share nothing.

-Jared

 

Whoopsy Daisy! I thought I read somewhere that some parts from the Windsor were interchangeable, went back and checked that post...turns out I read it wrong...in my books (yes my books) the 351 Modified is considered a big block,and I'm not the only one that thinks that.
Know it all... It's all good, I'm am deeply sorry if I upset you.

PS+ I just read that the 351M has the same crank as the Windsor. I am amusing that they are talking about the stroke then? Or are they wrong as well?

 

351 c/m/w=small block.

 

351W small block?? Huh,never knew that.

 

Do you have a C6 transmission? The Windsors and the Cleveland will not bolt up to a stock C6 different bolt pattern. The quickest way to tell what series of motor you have is by how many valve cover bolts 5= FE 352/360/390/427/428 6= Windsors 289/302/351 7= 385 series 370/429/460 8= 335 series 351C/M 400
As far as telling the difference between the 351C and 351M externally, i dont have a clue except the bolt pattern for the bell housing.
Hope this helps!

 

As an old fart who was wrenching on these trucks when they were new I can say that we never considered the 335 engines to be "big blocks". The 351Modified (as in modified Cleveland) and 400 were considered by us to be neither "big block" or "small block", terms that are really rather hard to apply to this engine family.

 

this is wrong. check the forum names in the engines.....it says otherwise.

 

This thread is a perfect example of why the small block \ big block names just don't work for Ford. What one guy says is a small block, another guy says is a big block...and vice versa. There is no common characteristic across the board that puts one motor in one category and another motor in a different category. Thank you Dr. Dirt for trying to set people straight.

If, however, people want to still insist on fighting this never-ending nonsense, it would make more sense to call the 351C and 351W small blocks because they use the "small block" bellhousing pattern (Windsor family, inline 6), and a 351M a big block because it uses the "big block" bellhousing pattern (429/460).

There's no reason to say "351 big block." Do you see why? Because if you say "351 big block," people have to ask you if you meant Windsor, Cleveland, or Modified. This very example of ambiguity is why it makes no sense to use this method. Just say 351M, 351C or 351W and then people will know exactly which motor you are talking about.

fast96 - I am sorry your simple question started this argument; if it is the original engine then it will be a 351M. It would have come with a 2 barrel intake and carb. As for the timing - is the emissions sticker still under the hood?

 

that's a lot. I try to keep the world moving better all the time.

 

You are ALL wrong, these engines must all be called "big blocks". Otherwise (and you can follow the logic here) we would be calling those 351's "small blocks", most modern V-6 engines "tiny blocks" and little 2L honda engines "micro blocks".

Hmmm... on second thought, let's just stick with engine names instead.