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Are the 351C big block engines?
I have seen many 71-73 Mach 1's on craigslist and E bay that have the M or Q-code 351C 4V engine advertised as a Big Block Mustang.
I am sure they are still small block engines since in order to be considered Big Block for me is that the engine must be at least 390ci and this one is not available in the 71-73 Models but the 429 was and that one would be considered Big block.
Am I correct and why would the 351 be considered big block by some owners....?? It may have the power but not the cubic inches
If the words big block appear in an ad when it is a 351c, either the seller doesn't know any better or they are just hyping up the excitement about the car.

[Image: 386_07_10_13_5_58_42.jpeg]
My Mustangs:
71 M-code Mach 1, Medium Blue/White Sport, 4R70W, 3L50, Factory Ram Air.
72 Q-code Mach 1, Pewter/Black Sport, 4-spd, 3L25.
65 Convertible, Britney Blue/White/White, more modified than original.
05 Convertible, Legend Lime/Tan/Tan, future classic??
You are correct, 351C is a small block, as are it's 335 series cousins, the 351M and 400M. It does get confusing, all FE blocks are considered to be big blocks, even the 332 and 352 engines. The 385 series is big block (429s and 460s). A lot of people don't have a clue as to what they have, and think that "big block" sounds better than calling it just a 351C, which is enough.

“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
351c is the first small block that could take out the big blocks on the track...Years of ford tech went into making a motor that was so good..It was banned from most racing....Had a smaller crank than any ford small block at the time...Meaning it could spin higher rpm's...Better webbing...Higher tech block casting..For a lighter but stronger block...Huge heads...What a motor...i would allmost put it in the class of small block with big block heads..lol<~~ but still that doesnt give it justice...Its more than that...Its a block all in its own class.

btw cubic inches doesnt not make it a small or big block....Pontiac and olds made a 350ci big block...and fords 352 is a big block too...if you put big heads on a small block...I won't ever call it a big block..cause the block is still small..lmao
It is a big block. The heads belong on a 429 and the intake
valves are bigger than the 460 police interceptor; 2.19 vs 2.07.
You can stick a tennis ball in the intake port on the head.
It is a big engine.


[Image: 1_11_11_13_11_50_27.png]
It is a Small Block. Here is a good link on it

It bolts only to small block pattern bell housings also.

Pete - MotoArts Decals and Signs
'71 Sportsroof 351C-4V/4-speed - FINALLY under construction - no, wait, on hold again...
'90 Mustang 7-Up 5.0 ragtop, rolling beater
'66 Sunbeam Tiger Mk.IA, survivor
Who Cares?

Big block/small block. The definitions are tossed around. In the end it really doesn't matter.

It's one of the best engines of its time. We know that for sure.

If someone asks me I say small block, based on the bolt pattern. But we know the other 335 engines including the 351M and 400M had the 'big' bell housing pattern (a few 400's came with the small pattern)

I used to spend time telling sellers 'that is not a cleavland, it is probably a windsor' only to be told I was wrong. I got tired of it. Smile

73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

Pics of modifications included in:
Here's a site that list the measurements of ford motors. You can decide for yourself. I don't classify it as either personally, I just say it's a Cleveland.


[Image: 36319488731_8f2a376549_z.jpg]
73 Mach 1 Mustang
89 Dodge Shadow ES
94 Jeep Wrangler

I agree i call it a cleveland. The original small block/ big block designation was to identify Chebby engines it does not really translate to other makes.
In the Ford world most people use "small block" to mean windsor(260 to 427 cubes),big block generaly means 385 series (429 to 600+ cubes). Everything else, IMHO is a FE, a Cleveland, a Mod(modular) or a flathead.

I expect to see a 429 type motor in a 71-73 Mustang if it claims to be a big block.

Blue Mustang,White Five hunderd, Red Escape
Red,White and Blue
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