I am now about to delve into the ‘murky’ world of Australian Ford engines. I am going to say up front that the information here has been gleaned from some years of following the Falcon GT scene through the Falcon GT Club of Australia to whose members I gratefully acknowledge their assistance and wisdom. Mistakes that appear here are most probably the result of me misinterpreting what I have been told or read. If there is anything glaringly wrong, please get in touch and point out my mistakes and I will correct it.

With the above in mind, I make no apology with starting off with the 351 ci Cleveland engine, as fitted most effectively to the Falcon GTs, but which also survived until 1982, Australian built and powering Australian Fords of many types. While the U.S. version of the 351C existed in factory vehicle production for only 5 years - 1970 to 1974 - the Australian ‘version’ ran from 1972 to 1982, nearly three times as long, and as such the Cleveland could be regarded as more Australian than American. Its popularity down under has spawned a thriving industry of tuners, machinists and performance parts suppliers providing many services at reasonable cost in comparison with those in the U.S. where the 351C is regarded as ‘rare’ and ‘exotic’ and the willingness of suppliers to provide support and parts is thus restricted by the engine’s perceived rarity, especially when compared with its Windsor equivalent, an engine that has a long history in the U.S. bringing availability, ubiquity and cheapness to the forefront.

351 Cleveland

Let’s start with a general overview, specifically an aid in identifying the Cleveland engine. Before the 351C, there was the 351W which was a 351ci capacity version of the original Windsor engine family - so-called because that is where the original engine factory was, Windsor, Ontario - which started life as a 221ci in 1962, but grew to encompass the famous 289 and 302ci versions through the sixties.

In these small capacity displacements, the 289/302 was a great little engine - and it went on to become even greater in the eighties and nineties - but as car size increased in the U.S. Ford decided that they needed larger capacity from the small block to generate more torque to move the heavier cars. Hence they developed the 351W, but even from its inception, Ford appreciated that while the 351W gave the capacity required, it was a marginal engine from the point of view of developing more and more horsepower as the performance wars of the late sixties escalated. So Ford designed the 351C.

The 351C was designed from the top down with the major ammount of effort put into designing the best and most efficient cylinder heads that they could to allow the engine to breathe, and so to rev.

The 351C has a canted valve cylinder head, with splayed valves set at slight angles to one another, unlike the 351W which has parallel valve stems. This canted valve arrangement makes the 351C cylinder heads bigger - wider - than those of the 351W, and as a result it has wider rocker covers. As an aid to identification, the 351W exhaust manifold to cylinder head surface is almost vertical as viewed from the ends of the engine, whereas the 351C has an exhaust manifold to cylinder head surface which sits at 45 degrees and is as near parallel to the side of the block. This can be difficult to see if an engine is in place.

So, the other easy means of 351W to 351C differentiation is to know that the 351C has a dry inlet manifold wherein cooling water does not pass from head to head through a passage in the manifold, but instead passes across the engine in a cast extension to the front of the block. This extension also provides a ‘recess’ for the timing chain and contains the thermostat housing. Simply put, the top radiator hose for a 351C goes vertically into the thermostat on top of this extension, and the 351W top radiator hose goes in horizontally to its thermostat as fitted to the front of the inlet manifold.

Okay, that was the easy part. Now we can look at different versions of the 351C. It is best to start out by describing how the Cleveland was designed for the Americans, before moving on to the Australians. Ford U.S. came up with two basic versions of their 351C, the 2V and the 4V. The 2V stands for, as it does most usually, 2 venturis, and describes a two barrelled carburettor. American 2V 351Clevelands came equipped with two barrelled carbs and as such the engine was designed to be the common version of the engine fitted to non performance cars. To this end, Ford U.S. designed a set of heads for the 2V that had smaller inlet and exhaust ports to promote better low down torque. These small port 2V heads required their own inlet and exhaust manifolds to mate up with the heads and they also had smaller valves. Initial rating of the 2V engine was 250hp.

The 4V was the performance version of the 351C, and was so named because it was designed to have a 4 venturi or four barrelled carburettor. To feed the extra fuel through the cylinders, the 4V heads had much larger ports than the 2V, and as result required their own matching inlet and exhaust manifolds, and larger valves. The combination of bigger, more effective 4 barrel carburettor, bigger valves and bigger ports ensured that the fuel mixture could get into and the exhaust gasses get out of the combustion chamber more effectively than in the 2V heads, hence the 4V engine would rev better and as a consequence, produce more power. The 351C 4V was rated, in 1970, at 300hp.

Engineering is often a compromise, and such was the case with the 4V. The valves, and especially the ports were so big that the inlet mixture could slow down in its passage into the combustion chamber. This decrease in velocity, most noticable at low revs, left the 4V versions of the 351C feeling kind of sluggish as the cylinders struggled to fill. The 2V, with its smaller ports and valves, could keep the mixture velocity up which promoted better cylinder filling, and gave the 2V its impression of greater low down power, torque and flexibility. Of course, this is what Ford U.S. wanted, promoting the 2V as the torquey grocery getter engine, and the 4V as the “let it rev and feel the power” engine.

In the U.S. for the very brief period that the musclecar/horsepower craze continued during the 351C’s early life, the 4V spawned a small clutch of developments:- the 1971 Boss 351; the 351CobraJets, or CJs; and four bolt mains caps. These were U.S. only developments and never made it to the Australian chapter of the 351C story to which we now turn.

The first 351C engines to appear in an Australian Ford were those fitted to the XW GT Phase 1.5s built in February, 1970. The U.S. 351C was announced for the 1970 model year and introduced in September, 1969, so it took less than six months for the Cleveland to appear in Australia. The Phase 1.5 - one and a half - was to all intents and purposes an XW GTHO with all the running gear from the 351 Windsor powered Phase1 but with an imported 351C 4V engines fitted. They were cars to tide the market over until the full production Cleveland powered XW GTs were released in April, 1970. The regular production XWGT, powered by the 351C, then ran out the XW model to October, 1970. Later, introduced in June, 1970, was the XW GTHO Phase2 fitted with the U.S. imported 351C engine which had a solid lifter camshaft, and a 780cfm Holley carburettor. You can see that the 351C was regarded first and foremost as its flagship engine.

With the October, 1970 introduction of the XY Falcon and ZD Fairmont range of cars, the Cleveland progressed beyond its performance image and 250hp, two barrel carburetored, 2V versions were offered as the top option on both models. The 300hp, four barrelled, 4V version of the engine was only offered on the XY GT and GTHO. Both these engines were still imported, but Ford Australia was keen to build its own and had tooled up to provide locally manfactured 351C and 302C engines. Why tool for a 302C engine when they had been using the 302W ? Well, it provided economies of scale, being able to use all of the ancilliary parts from one engine on another, and all for the sake of a different crank and rods.

And so the March, 1972 introduction of the Australian designed XA Falcon range also saw the debut of Australian built 351C and 302C in two barrel carbed, 2V form. There have been some reports that 302C’s were fitted to Brisbane built, December, 1971 XY Falcons. Brisbane cars have the letter ‘H’ as the second leter of their VIN. For the moment, the four barrel, 4V engines were imported, but by the early/middle of 1973 Ford Australia had developed their own four barrel fed 351C but used their own 2V style heads on the engine.

This is where the 2V and 4V descriptive terms become somewhat entwined. The distinct separation that applied in the U.S. between 2V and 4V ensured that a 2V Cleveland had a two barrel carb and inlet manifold, small inlet and exhaust ports and an enlarged chamber volume, while the 4V Cleveland had a four barrel carb, large inlet and exhaust ports and reduced size chamber volume which created a higher compression ratio. Now the Australians introduced a 2V head that took either a two or a four barrel carb inlet manifold, and had a large, but not as large as the U.S. 2V, open chamber size, plus, for further confusion, they introduced a 302C engine that had 2V heads which had a two barrel carb but a chamber volume smaller than anything the U.S. had offered, even on their highest performance Clevelands.

While the home grown four barrel, 2V 351C was introduced on automatic XA GTs towards the end of its life, the last of the imported, high compression, big port, 4V U.S. engines lasted only through to the first few months of XB GT production, again mostly, but not exclusively, in manual transmission cars, and by January, 1974, they were gone and all 351C engines that followed were Australian made.

The 351C ran through till the middle of the XE Falcon’s life before, to howls of protest, Ford killed off their V8 in 1982. In its later life it suffered compression ratio cuts, emissions equipment additions and a swap to Carter carbs to keep it clean and healthy, but, it started out as a romper stomper, so let’s look at its glory days, and hopefully explain some of the mysteries and anomalies.

We will start not quite at the beginning because I do not have a photo of a XW GTHO Phase 1.5, but with a Phase2.

Pretty impressive, but what do we look for ?

The first 351C’s were all imported from the U.S. and as such conform to how the Americans were building and tooling for their engines. So, firstly, Ford had a policy of giving their engines an engine code number. This should not be confused with the practice of assigning an engine code letter to the vehicle’s data plate or VIN. For example, 351C’s with four barrel carb’s fitted to GT’s used the letter ‘T’ on the compliance plate. The engine code number was a number assigned to a production batch of engines and is used to describe the engine in some detail, especially if it is used to identify the engine to a parts counter.

U.S. 351C’s used a code system that started with the letter ‘K’, and followed it with a sequential set of numbers running from 600 to 632. For example, ‘K625’ was the Boss351, and ‘K610’ was a ‘M’ letter code, 351 2V engine. I will not run through the whole list of U.S. engines, but instead concentrate on those that reached Australia. These were:-

K601, K604 and K614 which were 2V, two barrel carb engines as fitted to XY   Falcons and ZD Fairlanes. 

 K608 and K609 which were 4V, four barrel carb engines fitted to XW and XYs.

 K616 and K617 which were 4V, four barrel carb engines fitted to XA and early XBs.

Originally in the U.S. this number was on a metal tag that was attached to an ancilliary bracket or more usually sandwiched under the coil mounting bracket, but later in life they were reduced to a white paper sticker on the front of the right hand valve cover. The 351C’s built in the U.S. and shipped for export acquired the letter ‘C’ in front of the ‘K’ and became CK601, CK604, CK608, CK609, CK614, CK616 and CK617, and this is what appeared on the paper tag on engines fitted in Australia. This ‘C’ stood for ‘Canada’ as engines built for Canada could be exported to Australia without Australia paying import duty, as both were Commonwealth countries. The ‘CK’ engines are identical to their US conubterparts. It is also worth mentioning that in the US the switch from using a metal tag to a paper decal took place in Februay, 1973, yet the paper decals were appearing on Australian engines before that.

Here is an example of a coil tag that was fitted to an XA GT RPO83.

What is interesting about this tag is that XA GT RPO’s were built in August, 1973. The tag decodes as - ‘351C’, the engine; ‘72’, the model year; ‘5’, the change level or version; ‘G26’, 26th of July assembly date; and ‘CK617J1’, the engine code. On U.S. tags there is usually a digit in front of the ‘G26’ which signifies the year of production. The year is missing on this Australian or export tag which may have been a a deliberate policy to allow Ford to stockpile export engines, either in the U.S. or at their destination.

It is also worth mentioning that the equivalent paper tag for this engine reads ‘CK617J1-W’ and it signifies a special order, manual transmission only square block import engine with big port heads. Some more of what this means is explained below.

Here is an example of the paper tag for a ‘CK608’ engine, showing its location.

As these paper tags appear in several of the following pictures, here is a breakdown of their significance:

CK608 A1 70-1 - manual D block 4 heads (XW-XA)

CK609 A1 70-1 - auto D block 4 heads (XW-XA)

CK616 J1 71-3 - auto D block 4 dot heads

CK616 J3 72-5 - auto D block 4 dot heads (1971 casting

CK616 J3 72-5 - auto square block 4 dot heads (1972 casting)

CK617 J1 71-3 - manual D block 4 dot heads

CK617 J1 72-5 - manual square block 4 dot heads

CK617 J1W 72-5 - manual square block 4 dot heads

Some of what the descriptions mean will be explained below.

Regarding coil tags, and by way of comparison to the previous one, here is the tag for an early XY GT.

This shows that it is a:- ‘351C’, engine; ‘70’, model year; ‘1’, first version; ‘A18’, 18th of January engine build; and ‘CK609A1’ engine code. This is a ‘D’ block code.

As a check, here is the block from that engine showing the casting numbers:- ‘DOAE-J’, is the ‘D’ block casting and - not too well reproduced - under it is the casting date, ‘9M13’, 13th of December, 1969.

It was mentioned above that in the US they changed to engine code stickers in February, 1973. This is what they looked like, and note they were on the drivers side - in Australian terms - front face of the rocker coverand not the pax side.

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 ‘D’ block or the ‘square’ block

The terms ‘D’ block and ‘square’ block apply to differences in the casting of the engine block. The ‘D’ block is the earlier casting, in fact the initial casting of the 351C block and the ‘square’ block is the later one. How much later is open to conjecture. ‘Square’ blocks would appear to have been available in the U.S. in 1971, and there is some evidence to show that the ‘square’ block appeared in automatic XY 351C 2V’s as early as May, 1971, and in manual XY 351C 2V’s in December, 1971. It does appear that XY 351C 4V engines continued with ‘D’ blocks. What can be said though is that no XW or XY GT came with a square block, and that all Australian built engines are patterned after the ‘square’ blocks.

The ‘D’

The ‘D’ can be seen on the cast extension on the front of the block, adjacent to the petrol pipe.

Compare with the later square block.

For XA GT’s, the switch to square blocks appears to have taken place in May or June, 1972 for automatic trans equipped cars, and in August or September, 1972 for manual trans cars.

As mentioned earlier, the square block seems to have appeared in the U.S. in 1971, as the engine fitted to 1971 Boss351 Mustangs were square blocks, as below.

It is worth noting also that Boss351 blocks were also four bolt main blocks.

Australian manufactured blocks have the letters ‘GF’ cast into them at the rear, upper surface beside the oil pressure gauge adaptor. ‘GF’ stands for Geelong Foundry.

US blocks had ‘CF’ for Cleveland Foundary cast here, and early Australian cast blocks were ‘CF’ as well as they used the US casting moulds initially.The change from the ‘C’ to ‘G’ cast would have been relatively easy to carry out.

 Cylinder heads

To fit 351C engines, it is generally accepted that there are seven types of production Cleveland heads that you may come across, five U.S. and two Australian. They are:-

U.S. 4V Closed chamber with a ‘4’ cast in the corner

U.S. 4V Open chamber with a ‘4’ cast in the corner

U.S. 4V Closed chamber with a ‘4’ and a ‘dot’ cast in the corner

U.S. 2V Open chamber with a ‘2’ cast in the corner

U.S. 2V Open chamber with a ‘2’ and a ‘dot’ cast in the corner

Aus  2V Open chamber with nothing cast in the corner as fitted to Aus 351C

Aus  2V Closed chamber with nothing cast in the corner as fitted to Aus 302C

To take them in turn.

The U.S. 4V closed chamber head with the ‘4’ casting is the head fitted to the CK608 and CK609 engines installed in XW and XY GT’s. These heads were fitted to imported ‘D’ block engines.

The U.S. 4V open chamber head was not fitted to any Australian Ford.

The U.S. 4V closed chamber head with the ‘4’ and ‘dot’ casting is the head fitted to the CK617 engines installed from mid 1972 XA through to end of 1973 XB manual transmission equipped GT’s. It has a slightly larger chamber than the ‘4’ only casting with a resultant half a point compression drop in C.R. These engines were imported ‘square’ block engines.

The U.S. 2V open chamber head with the ‘2’ casting is the head used on the CK601 and CK604 engines in XY’s and ZD’s. These were imported ‘D’ block engines.

The U.S. 2V open chamber heads with the ‘2’ and ‘dot’ casting in the head were used on the CK614 engines fitted to late XY’s and ZD’s. These engines were imported ‘square’ block engines.

The Aus 2V open chamber head with no casting mark is the head fitted to Australian built 351C’s fitted to XA’s through to XE’s with both four barrel and two barrel carbs.

The Aus 2V closed chamber head with no casting mark is the head fitted to Australian built 302C’s fitted to XA’s to XE’s with two barrel and four barrel carbs. It has the smallest chamber size of any of the production Cleveland heads.

So where are the cast marks ?

If they are present, they are in the top corners of the cylinder heads, visible because the rocker cover has its corner angled. In the photos above and below, you can see the ‘4’. These are XW GT’s.

And the ‘4 dot’ ?

As fitted to XA’s.

And so to put some of this in context.

Here is an XY GTHO.

And here are the features we have discused so far:- CK608, ‘D’ block and ‘4’ cylinder heads.

Here is an XA GT.

CK617, ‘square’ block and ‘4dot’.

There are, of course, some strange anomalies.

This is a July,1972 XA GT.

It has a ‘D’ block and ‘4’ heads. A leftover from the XY perhaps.

Here is another, showing an original factory rocker cover sticker in place.

Later Australian 351C’s, like this 1974 XB GT, had Australian ‘square’ blocks and Australian cylinder heads with no casting mark.

Note this June, 1974 XB GT has the the third type, or Australian, rockers covers, as described later, and the location of the engine/VIN stamping on the block - on the vertical face of the timing chain block extension..

This 351C in a September, 1973 LTD Landau also has the Australian style open chamber heads with nothing cast in the corner.

By way of comparison, and as an aside, here is a U.S. 351C 2V engine in