New to the big V8s and have seen discussions about both engines. What are the differences between the two and benefits for having one over the other?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

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Thanks,<o></o>

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Steve

 

You can read about the differences in the related engine forums
https://www.ford-trucks.com/forums/9...-and-351w.html
or this page

http://www.fordclassics.com/enginespecs.html

The 70's F-series trucks DIDN'T have 351W's in them so they don't really relate to this forum.

They were put in E-series Vans

 

But they swap in really easily, thankfully.

 

Another difference is the 351M is like a de-stroked 400. Kind of like a 360 & 390

 

351m have a bad reputation for being gutless, impossible to hop up, and gutless. Oh, I said gutless already. They dont make much power, but they can last for a long time.

The 351W is a good motor all around. I would take it over a 351M/400 any day.

 

351M/400 was originally based on the 351c 2v. The biggest problem with it is that it received a bad rep at a time when most motors were making about the same horsepower numbers in cars. It lead to a rather small market for making the motors decent. The upside is that the 400 can use a majority of the 351c parts to make it so but the 351m is not so lucky, but a 400 crank with 400 pistons can give it the oppurtunity. Also, these engines were made at a time when leaded fuel was plentiful and requires hardened valves for the unleaded fuels available, not really a big deal. The 351M/400 late models used the 460 bellhousing for the transmission pattern but required a longer input shaft for manuals than the 460. Some early production 400 did recieve a dual pattern of the windsor/cleveland pattern as well as the 460 pattern. A good portion of the 351M/400 series were retarded at the timing chain from the factory. There was some claims that the demise of the engine at ford was because of the factory smog, which would have easily been corrected. I believe it simply was not a well received motor by the public, much like the problematic 6.0 diesel, so Ford just quit production and focused on the windsor blocks just to get rid of a problem child that could have been corrected easily.

I kind of liked the old 351M in my truck until it became so burned up that it would not run anymore with out smoking. Overall, it did its job with only minimal complaint and no rebuilding of it. I am thinking of a windsor swap simply because I would have access to overdrive transmissions with minimal need of checking clearances and computers for the E4OD. The only overdrives for the 460 were the ZF 5spd and the E4OD which would work on the 351M/400 but would require checking and modifying clearances for the flywheel and clutch to get it to work properly. It is kind of sad to consider a motor swap just to get access to different transmission options to get the old body to continue for another 20 years, but old metal never dies it just rusts away.

 

i don't know about the gutless part. the 351M in my 79 F250 4X4 will put the truck sideways in the road if you give it to much go pedal in turns, and roast the tires off it from a dead stop.

it has also been known to pull a 17,000 lb mini excavator all over the state of new jersey without complaining about anything except for a want for more gas in the tank.

 

Yeah, a 351M will roast the tires, if you dump the clutch at 4500 RPM, with hard skinny tires. A limited slip or a locker will cause cornering problems under power. Are you the orig. owner of the truck? My guess is that somebody did something to it...

 

i bought it 3 months old with 1500 miles on it. it has a C6 trans, and 12.5X33X16.5 tires on it, and the only thing i have ever done to it was put an edelbrock performer intake with a 600 cfm holley carb, and a 3 inch exhaust from the y pipe back on it back in 80 when i first got it.

 

My uncle had a 79 Bronco as well as a 78 F250 4x4 with the 351M in both. Uncle Lynn was always the one that had to pull everyone else out at the gravel pit and was also the one that coudl roast his "Power Cat" (remember those?) 38" mudders at will with no midifications more than dual exhausts. Ahhh...those were the days....$1.18 / gal gasoline...
My brother, on ht other hand had his '79 F250 CC (which did come with a 351W) that would not pull the hat off of your head. Yes I did confirm with both my brother and uncle about the motors in all 3. All three were bought new in Paris, TN by my brother and my uncle.

 

On our farm we have a 77 F250 351M, auto, 2WD, that has been run hard its whole life, and is still stock, its what I drove throughout highschool (i wasnt nice all the time.)

With close to 200000 hard miles on it, that thing will roast tires on demand, no questions asked. On the highway, I have had the needle pointing past straight down, coming up on 0 again. That thing flies. I have nothing but respect for that 351M, and while performance parts arent abundant, there are a still parts out there to wake them up more.