351c or 351m

[youngpup03]

allright i need help i admit i love chevy but i recently bought a 1970 ranchero with a 351c in it (8bolt valve covers) is there a simple way to tell if it is a 351m it is 2 barrel but 351c came with 2barrel as well as 4 barrel while the 351m only came with a 2barrel i need to know whats an easy way of identification on these 2 motors with out much dissassembely it has me seriously in aw hoping its not a 351m but that the mystery motor is a 351c plz reply or email me
[email protected]

[Dan_in_WA]

If it's the original engine, it's a 351 Cleveland.

The 351 Modified didn't come out until 1975 or so. Ford built that because they ran out of 351 Windsors, so they put 351W cranks in a 400 block and called it 351M.

[HiFlow5 0]

Dan is right about it being a 351C if your truck is a 70. In 74 the Cleveland was discontinued, and the 351M was born, but only in full size passenger cars. (the M actually has no meaning other then an internal Ford reference to differentiate between the Windsor, and Cleveland). The 351M was not used in trucks till 77, and production of the block ended in 79, but the motor still popped up in Bronco's till 82.

But the reason Ford went with the 351M in not because they ran out of Windsor blocks. That is totally false!

The 351 Windsor engine was designed for higher RPM duty in small to midsize passenger cars. The 351M is actually a de-stroked 400 motor. The 351M was mainly designed to meet the newer tough emissions laws that the older (360/390/428) engines wouldn't be able to meet. The 351M was also designed as a low end torque motor to replace the above motors in passenger cars.

[NavyMike]

This is great information but no one addressed his question, and , I also would like to know if there is an evident way of telling the difference from the outside appearance?

[redneckdrfm]

Originally Posted by NavyMike

This is great information but no one addressed his question, and , I also would like to know if there is an evident way of telling the difference from the outside appearance?

yea, u can the w has 5 bolt vavle covers and the radiator hose goes to the intake manifold.
the c has 8 bolt valve covers and the radiator hose doesnt to directly to the intake manifold.

[ervinj]

the valve cover bolt config. will tell you if the heads are c or w but the best way to tell is the engine ID no. on the back of the block, a small mirror on a swivel head might be helpful along with a can of brake cleaner.

ervinj

[zxkevinxz]

i have a 351c torn down to the block on a stand. i have other projects but i'm cleaning this one up in my spare time. keep me posted on how yours turns out or any problems you have along the way.

[n2racing]

The quickest way to tell the difference is the spacing between the top two bellhousing bolts. 351C are 5inches on center. The 351M is closer to 7inches.
I hope this helps. If you need any other help write me at [email protected]

[Mercracer]

From the front of the engine, it is similar to telling the difference between a 302 and a 351W.
If the distributor mounting hole is even with the front mounting surface of the intake manifold, then you have a 351C. If the mounting hole is deeper into the block, then it is a 351M. The front inner corners of the cylinder heads are also raised above the distributor hole on the M vs the C.

[who fan]

My experience with these motors is limited. My opinion is the 351C is a bad ass engine and 351M is a good boat anchor.

[racercarsman]

i have a 351m in my 73 ford ranchero. the way to tell the difference between the two is that the 351m has a ridge that sticks out from the block on the front right next to the distributor

i myself dont see why every one is doggin the 351m it was mad to replace the 351c/w. the heads onthe 351m are the same as the 351c are the same as the 400/351m exept they have canted valves, wich means they are angled in the head to have greater flow. alsothe differences between the 351m and the 400m are the crank shaft and the pistons, its not a windsor crank in the 351m. the m-series is made for gobs of low end torq and power.

[Paul Masley]

I had a 351M in an 85 F150 4X4. Could not kill the thing. When truck was totaled in 1992 it had over 300K. The only thing replaced in the engine was the timing chain and gears. Bet you could have pulled a head and looked through and could see the crank. That truck got 22 mpg, regardless of it being empty or fully loaded, creeping in town or blasting down the interstate at 80. I would love to find another one.

[jerryred]

there is a great web site for the reason for ID of 351 c m just punch in 351m or c if you find a place with bubba on it your there all you need to know
this site helped me sort out my 1977 351m problem
I bought a 1958 tudor 300 and the guy insested the engine was a 1971 torino but after looking at some of the ID numbers I knew something was wrong. after I found this the 351 site I now know that the motor is a 1977 or so F 150 but it is still a good project car and hope to have fun with it

[Samw]

Actually, the "351m" and the "c" are both antique, boat anchors.

The late model 5.8L Windsor is a better engine.

It's a shame Ford discontinued the 5.8L in favor of the 4.6 and 5.4, overhead-cam wheezers.
A sorry bunch indeed. If Ford wanted an economical powerplant, they should have re-issued the flathead. True, it burned a lot of oil, but you can't have everything.

[miverson332]

??? Lost me.