Which 351C

[tdlmomowers]

I bought a 1969 Ford Torino GT in Sept. of 2008. The car has a 351C engine in it. All the information I can find on these cars, say that the original engine would have been a 351W. The engine has been clearly replaced with a newer engine. The numbers on the exaust manifolds indicate that the engine is a 72. The engine has an aftermarket 4 barrel intake and Holley carb. on it. The engine runs well with no smoke and has 60 psi of oil pressure, so there doesn't appear to be anything wrong with it. My question is, how can I tell if my engine was an original 4 Barrel engine, as I know the cylinder heads were different depending on whether the engine was a 2 Barrel or a 4 Barrel. Could I tell the difference if I removed the valve covers and looked at the valve location or rocker arms? I need to replace the valve cover gaskets anyway as there is a little seepage from old gaskets.

[Milt/Las Vegas]

If the aftermarket intake is an Edelbrock,it will say 2V or 4V on it in front of the carb.Edelbrock is the only company I know of that made a 4V intake for a 2V 351C engine.The 4V head castings go straight down from the top exhaust manifold mounting holes ,whereas the 2V castings dish in.4V exhaust manifolds will bolt up to 2V heads but leak on the sides because of this.This's probably as clear as mud.

[tdlmomowers]

The intake is an Offenhouser Dual Port. The Carb is a Holley 4160, 600CFM with vacuum secondarys.

[Merc Cruzer]

I am not sure if this will make you feel better about the 351 C, but it is a large block engine whereas the 351 W was a small block. The 2 bbl heads flow better than the 4 bbl heads, especially with the Edelbrock 4 bbl manifold and 4 bbl carb. Basis for this statement: we restored a 1970 Cougar XR-7 for my wife (it was what she drove through college) that she just loves and it came with the 351C 2 bbl and we did the Edelbrock 4 bbl manifold. The only reason I would change it is if you want to show it for points....and that might not be a good rason as the aircleaner covers just about all of it.

[tdlmomowers]

The car is being done as a Driver. The stock air cleaner was gone when I got the car. If there was any emissons equipment on the engine, they were all removed before I got it. It has the single vacuum advance unit, no AIR pump, just the PCV system. The engine starts easy, idles great, seems to have adequate power, does not run hot, has good oil pressure, and does not smoke, and no ticks or rattles.

[craig]

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Actually a 351C was never considered a big block engine. You don't have to pull the valve covers or anything else to determine whether it is a 4V or 2V. Look at the top of the heads right above where the valve covers sit, close to where the intake man. sits, there is a mark, either 2V or 4V. The 2V heads were all open chamber, smaller valve and port size, while the 4V stuff is larger and came first as a closed chamber(Ford called it a "quench head") and in '72 it became an open chamber. The basic blocks are the same, some were 4 bolt main and some were 2 bolts, I have seen both with 2V as well as 4V heads, from the factory. The pistons in all the 70 and 71 engines were originally flat tops, in 72 they went to dished pistons in all the engines to lower the comp even more on the 2V and 4V. Because of this the big valved 4V headed engines dropped to 8.9 to 1 compression ratio and were poor performers. Many guys will argue that the 2V heads will perform better with a 4V intake, but, I can't agree completely. I ran a machine shop from the late 60's thru the late 80's and built many cleveland series engines, for anything from a 4X4 to low 10's Mustangs and in most cases the 4V's worked better. With todays gas the 2V will no doubt make more useable low end torque on a basically stock engine

[darrell]

the 2v heads give you good bottom end power.the 4v heads are for top end and are poor for street.these are the same head used on boss 302 .away to much port for a little engine.

[Merc Cruzer]

Food for thought:

Remind folks that there is no such engine as 351!
They are ALL 352s, no matter if they are small block, big block, or FE.
In the late sixties when they were developing Windsors, Modifieds, and Clevelands, remember Ford dealers were still doing warranty work on 352 FEs!
They called the newest 352 a '351' to avoid confusion. We now call it 'Windsor'.
Then they made it worse by adding the 352 that we now call a 'Cleveland'.
Shortly thereafter came a tall block 'Cleveland' 352 (and identical 400) that needed a name... They called it 'M', and it had a small block bellhousing for part of the first year. Before the end of the year it went to the Lima big block bell. Ford never made it clear what the 'M' stood for, but folks have made up things over the years... Midland, Modified, Michigan, etc...


ratio411

[tdlmomowers]

Thanks for all the replys. Your information is very useful. It would appear from the information that you guys have given me, that my engine has the 2 barrel heads on it. At the front top of the heads,by the intake manifold there is a "2" cast into both heads. I think this engine may have come out of a full sized 72 Ford or Mercury, don't really know for sure and can't get ahold of the previous owner.

[Bill Steiner]

I know in 1970 Merc. Cougar had ether 351 C or 351 W. All the 351 C where 4 bl , all the 351W where 2 bl. They where both called small blocks. I ran a linc Merc shop back then. I still have the 70 Cougar 351 W that my mother bought new then. Bill

[darrell]

way back you could put something together called a street boss.it was a 302 with 2v cleveland heads.a special intake was made to fit.it was a great was to spruce up a 302 without goine to the hugh port boss heads.this was back before all the after market heads came along.havent heard of one for years.

[craig]

Using cleveland heads on both a 302 and 351W has made quite a comeback. Edelbrock is producing manifolds for both apps. and will work on either 2V, 4V, Austrailian or their own cleveland style heads

[deucemac]

Originally Posted by Merc Cruzer

Food for thought:

Remind folks that there is no such engine as 351!
They are ALL 352s, no matter if they are small block, big block, or FE.
In the late sixties when they were developing Windsors, Modifieds, and Clevelands, remember Ford dealers were still doing warranty work on 352 FEs!
They called the newest 352 a '351' to avoid confusion. We now call it 'Windsor'.
Then they made it worse by adding the 352 that we now call a 'Cleveland'.
Shortly thereafter came a tall block 'Cleveland' 352 (and identical 400) that needed a name... They called it 'M', and it had a small block bellhousing for part of the first year. Before the end of the year it went to the Lima big block bell. Ford never made it clear what the 'M' stood for, but folks have made up things over the years... Midland, Modified, Michigan, etc...


ratio411

Ford made it VERY clear to us Ford mechanics that worked on them at the time and the new car books that were issued to us then stated that it was a 351 MODIFIED and not to be confused with the 351C or 351W. It was called a modified because the block is in fact a 400 tall deck using a short stroke to arrive at 351 (352) cubic inches. It was designed strictly for smog and nothing else Appearantly (and I'm guessing on this) the rod angle in the tall deck was easier on pollution production. The lousy part is that each of the 351/352 engine used different bellhousing patterns and would not interchange unless the correct transmission was used. Another reason Ford handed the performance world to Chevy on a silver platter. I told that to Ford execs at SEMA a few years ago and gave references. They weren't pleased at my discertation but one reluctantly agreed with me.

[raceron1120]

Originally Posted by deucemac

Ford made it VERY clear to us Ford mechanics that worked on them at the time and the new car books that were issued to us then stated that it was a 351 MODIFIED and not to be confused with the 351C or 351W.....

Yes, that's consistent with what I was told too. I was a parts manager in the 70s and when the 'new' 351s started showing up with the "M" designation, Ford told us "Modified". Short definition they used was '...modified Cleveland-style engines, to comply with emissions-related requirements...'

Not being a mechanic I wasn't nearly as tech savvy about the specifics as you deucemac, but the Ms were certainly different from the earlier Cs, as you pointed out.

The mid 70s was a transitional period when the manfucturers were moving from hi-po to low-compression, emission-compliant powerplants as mandated by Big Govt. Working in the business at the time, there were some serious quality issues and resultant customer dissatisfaction with a lot of the product that was on the market. Remember the '74 Mustang II? Pinto? Courier? Whew!

If I remember correctly it was the late 70s 351M/400s that were recalled for cracks in the valley along the cam bearing area?

But back to the original 351s in '69 - if I recollect, all '69s were Windsors. They had some issues with valve 'clatter' and Ford had either a "fix it when the customer complains" TSB, or a recall on them. The fix was to oversize ream the valve guides and sleeve them in order to eliminate the clatter.

'69 was recall-rich for the customers, but must've cost Ford a chunk of $$$. There were huge rust repair recalls in the early 70s to cover many '69 models too as I remember. Pickup boxes, Bronco boxes, fenders, passenger car 1/4 panels, doors....
Ron

[deucemac]

Those valley cracks ran along the lifter bosses and were all too common on 351M and 400's. The A40 campaign as I recall, put lots of bans on my plate at the time. We wold do the work and the rep would come in and examine the block to verify the crack(s) and then punch a hole in the side of the block to prevent some people from reusing the block for a false claim. Watched a deal lose his agency by reselling Ford false claims because a new rep didn't catch on at first.

[LOWRIDER]

Originally Posted by deucemac

Those valley cracks ran along the lifter bosses and were all too common on 351M and 400's. The A40 campaign as I recall, put lots of bans on my plate at the time. We wold do the work and the rep would come in and examine the block to verify the crack(s) and then punch a hole in the side of the block to prevent some people from reusing the block for a false claim. Watched a deal lose his agency by reselling Ford false claims because a new rep didn't catch on at first.

A dishonest dealer. Oh my. I worked for Ford dealers 40+ yrs and saw that and many other things. In regards to the 351M engine I found that if you advance the cam 2* you wont believe how good it runs. Did that to my 79 Ranchero and thought I had a new car.

[Dave72dt]

Ford was good for doing that. Easy way to kill the horsepower by retarding the camshaft. I know they did that on the 429 also. Ran the same cam but different timing gear. Put the early gears on and they come back alive.