Putting 351 heads on a 302 is still a hot topic that many drivers want to know.
For all car lovers, there’s no need for a specific reason to start a full bolt-on and learn how to put 351 heads on a 302.
However, is it ok, or will you have bad compression?
Let’s discuss the header choices more in the following sections!
351 Heads On A 302 – Is It Possible?
Can you put 351 heads on a 302 Ford?
Yes, you can do it. In general, it will not affect anything or bring you any specific benefit unless you have an old casting.
In the late models, the heads are kind of identical, making it possible to apply 302 heads on a 351 and vice versa.
According to Ford Power Books, in old models of the early ’70s (69-72 head), 351s already had slightly larger valves. In 1973, their valve sizes were the same, yet 351s still had bigger ports.
In the late ’70s, both 351 and 302 had the same valves and ports, though the former came with a larger combustion chamber size.
Are there any benefits of 351 heads on a 302? This enclosed space is known to reduce compression for emission reasons.
In 1987, both were designed with the same heads with E7TE castings. The only difference left is the head bolt size. The 302s use a 7/16-inch head bolt, while the 1/2-inch one is for the 351s.
However, it doesn’t really matter. You can get stepped head bolt washers to reduce the head bolt size or easily find aftermarket 1/2″-head-bolt-hole choices at an affordable price.
Make sure you know how to distinguish between the head studs and bolts.
Getting these bolts from Edelbrock, Ford, or even ARP is also possible. So, you can use 351 heads on a 302 engine.
How Many Types Of 351 Are There?
I often see the Windsor or 351W under the hood of older Ford cars and trucks. It’s named after its factory in Windsor, Ontario, and it’s a member of the Ford small block Windsor V8 family.
Compared to other siblings, I notice that it has a unique firing order, a taller deck height, and a longer stroke.
Putting 302 heads on a 351 Windsor is possible. The Windsor is more common than the Cleveland style head, and you can find a lot of aftermarket choices for it to make the changes.
You can use 302 heads on a 351 Cleveland. Let’s learn more about this 351C engine.
It was the product of Ford’s Cleveland, Ohio factory and part of the 335 engine family. It was well-known for its stronger crankshaft and better-flowing cylinder heads.
Ford designed the 351C with both 2V and 4V cylinder head versions. However, the brand only produced them for five years in the US.
If you ask, can I use 302 heads on a 351 modified, then the answer is yes.
They work fine because the 351M belongs to the same series as the 351C and is developed based on that faded-away version.
It has a 3.5-inch stroke, the 400’s deck height and a 2-barrel carburettor.
How To Distinguish W, C or M?
Since there are different types of 351s, they have some differences that you may need to pay attention to.
Below are tables comparing the visual differences between 351W and 351C/ 351M and between 351C and 351M.
|Number Of Intake And Exhaust Valves’ Covers||6||8|
|Radiator Hose||out of the top of the engine||installed into the intake manifold|
|Timing Chain||on the front of the enginecast aluminum external timing cover||recessed into the front of the engineflat metal timing cover|
|Intake Manifold||More narrow||Wider|
|Bellhousing Bolt Pattern||Windsor family’s pattern||385-series Ford big blocks’ pattern|
|Motor Mounts||2 bolts||3 bolts|
351 Vs. 302 – What Are The Differences?
It’s ok for the SVO 351 heads on a classic 302 engine. Yet, you still can spot the difference between them when installing by looking at the engine’s front side.
The 351 blocks are taller, allowing the distributor mount to stay below the block surface where the intake sits.
Meanwhile, since the 302s are smaller, this detail almost reaches the top of the block.
The 351s also have more space between the cylinder heads and the water passages, while the water passages of the 302s also are located right at the top.
Putting 351 Windsor heads on a 302 may increase the power. It does, but the difference is not that much noticeable.
Both engines perform almost the same at the point of optimized jetting and ignition timing.
The 351s generate a peak horsepower of 383 at 6,200 RPM and 391 lb/ft of torque at 4,000 rpm.
Meanwhile, these figures for the 302s are 374 hp at 6,700 RPM and 324 lb/ft of torque at 4,300 rpm.
Since there’s almost no difference, having 351 Cleveland and Windsor heads on a 302 block should not be a matter.
Will 351 Cleveland and Windsor heads fit on a 302? Though both have some more differences, they’re not a big deal. You can look at the table below to see how similar they are.
|Engine Size||Stroke||Deck Height||Bore|
|302 c.i.d. / 5.0L||3.000 in.||8.201 – 8.210 in.||4.000 in.|
|351 c.i.d. / 5.8L||3.500 in.||9.480 – 9.503 in.||4.000 in.|
The Bottom Lines
It’s possible to have 351 heads on a 302. It will work just fine and will not affect the engine’s performance.
Putting 351 Cleveland and Windsor heads on a 302 is not difficult.
You can do it by the stepped bolts of washers for the head swap process or by finding the aftermarket details to get the job done.
I hope my sharing will be of great help. See you in my next post!