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Discussion Starter #1 (Edited)
How do you identify a 351 4V Cleveland engine and ...?

How do you identify a 351 4V Cleveland engine and a 9” (3.50 Ratio, traction-lok) rear end?
Are there any numbers to look for? Are there any distinct external features to look for?

A couple of pics below.



Thanks in advance.
Raj
 

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While 2V and 4V heads look the same externally there are a couple of ways to distiguish the heads with the first being either a "2" or "4" stamped at either corner of the head towards the intake manifold:



If the intake manifold is removed you can tell by the difference in port size as 4V intake port measures 2.50 x 1.75" vs the 2V 2.02 x 1.65". Here is a pic showing the difference between a 2V and 4V intake port:



As for the rearend, you will have to find the tag that corresponds to the year, ring gear size, and gear ratio (usually bolted in the 9 o'clock position to the ring gear housing). Generally the tag is layed out to where, in the case of a 3.50" Traction lok, the lower line of the tag would read 3L50 (where the "L" denotes the TL) and the 3 and 50 denote the ratio, followed by a 9 stamped to the right to illustrate the the size of the ring gear.

I hope this helps!
 

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Corey,
Thanks for such a knowledgeable response. This info is valuable to the vintage mustang community.

I have a couple of follow up questions.

I am assuming that the block for all 351 Cleveland engines are all the same irrespective of 2v or 4v, but how do you identify a 351 Cleveland block? Is it just in the stamped vin or is there a casting number to look for?

I hope the tag is still there. If not, can any 1970 Mustang diff be built to 3.50 Ratio, traction-lok spec? How would you make sure that what I have (shown in the pic) is actually a rear end from a 70 mach-1?

I haven't taken delivery of the car yet, but want to be as informed as possible while doing the final inspection.
 

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I've always been told that 1 quick way to identify a 9 inch rear end is that you can not get a socket on the bottom 2 nuts of the pumpkin on a 9 inch. On an 8 inch you can, but you must use an open ended wrench on a 9 inch. Was certainly true for the 9 inch I picked up a couple months ago.

EDIT: On a Cleveland, I believe the valve covers are squared, compared to a Windsor block (289, 302, or 351) which would be angular. Here's a pic of my 289 to compare. Notice the curve in the valve cover compared to the ones you posted which were squared.

If I'm wrong, someone please correct me.

 

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Discussion Starter #5
PB65stang,
Thank you. A friend of mine just responded to me via email with the same exact answer you gave me regarding the valve covers. I think you are right.
 

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If the tag is missing on the 9" you can jack it up to check the ratio and posi. With both wheels off the ground if you spin one wheel and the other turns the opposite way its an open rear, spin the same way posi. While the wheels are up turn the wheel one turn and count how many times the driveshaft turns this will be the ratio. IE one turn of wheel = 3 1/2 turns drive shaft= 3.50 rear. You can build any 9" to almost any combination you want. Hope this helps
 

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Corey,
Thanks for such a knowledgeable response. This info is valuable to the vintage mustang community.

I have a couple of follow up questions.

I am assuming that the block for all 351 Cleveland engines are all the same irrespective of 2v or 4v, but how do you identify a 351 Cleveland block? Is it just in the stamped vin or is there a casting number to look for?

I hope the tag is still there. If not, can any 1970 Mustang diff be built to 3.50 Ratio, traction-lok spec? How would you make sure that what I have (shown in the pic) is actually a rear end from a 70 mach-1?

I haven't taken delivery of the car yet, but want to be as informed as possible while doing the final inspection.
Easiest way to determine if you have a cleveland is to look at the thermostat housing on the block. All 335 Series engines (351C/M, 400) have a "dry" intake manifold and as such the housing bolts perpendicular to the block as shown in the pic at the left. All 90* V8s (221, 260, 289, 302, 351W) have a "wet" intake as the thermostat housing bolts directly to the intake manifold, parallel with the deck of the block, as illustrated by the right hand pic.

Also if you look at the pics you will notice that the profile 351C Valve covers angle down, whereas the 302/351W are rectangular.

Hope this helps!
 

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jredline, where is the car on the right from since it's a right hand steer car hence the brake booster on the right side.
 

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The other easy way to tell Windsor blocks from Cleveland blocks is to count the valve cover bolts. 6 for a Windsor, 8 for a Cleveland. Yours does look to be a Cleveland.
As far as being a 4V, the number on the corner is the easy way to tell, but it may not tell the whole story. Early 4V heads are different (and better) from later 4V heads, in that the combustion chambers are much smaller, using a quench design. Pull a valve cover, check the part number cast into the valley. Its only 8 bolts. :^)
The rear use the bottom two bolt trick, yours looks to be a 9".

Carl
 

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jredline, where is the car on the right from since it's a right hand steer car hence the brake booster on the right side.
Australia; I believe it is a 1969 XW Falcon. It was one of the first pics I found when I googled 351W lol.
 

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jredline, where is the car on the right from since it's a right hand steer car hence the brake booster on the right side.
I don't think there's a brake booster in that pic. I think what you're seeing is the top of a coil over shock covering the hole for the heater blower motor. The hole for the booster is on the left hand side of the car (right side of the picture).
 

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I don't think there's a brake booster in that pic. I think what you're seeing is the top of a coil over shock covering the hole for the heater blower motor. The hole for the booster is on the left hand side of the car (right side of the picture).
wilit,

I believe My67Vert was referring to the 351W shown in the XW GT on the right pic:

 

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Early 4V heads are different (and better) from later 4V heads, in that the combustion chambers are much smaller, using a quench design. Pull a valve cover, check the part number cast into the valley. Its only 8 bolts. :^)
The rear use the bottom two bolt trick, yours looks to be a 9".

Carl
Here is a pic of what Carl is referring to:



Side by side, 351C high- and low-compression chambers are easy to spot. On the left is the open 73-77cc chamber (low compression). On the right is the 61-67cc closed chamber (high compression).
 
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