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My lovely Bride bought me an Elite Marti Report for my (50th) birthday. Marti sends out an email first with the Elite report as a PDF attachment. I probably won't get the real framed one until sometime in February. The stats look pretty cool. The IMPORTANT DATES section does not include a SOLD date, I'm assuming because it was ordered then shipped to Germany for final sale. I need to ask the Marti report folks on that one. If anyone does know why the SOLD date is not on there, please let me know.

 

Well my Elite Marti Report has finally arrived. Turns out the car is actually a one of one. I know what that means, but I'm not really sure exactly what that has an affect on. Does it make the car more valuable? More special? I know it's really special to me... I think I'll post a thread in the to see what you all think of a one of one...

 

The Report...

DSCF6821.thumb.JPG.b305b27ee1d670951fcd5aba3ed04063.JPG

 

The Stats...

DSCF6832.thumb.JPG.3c974532df9dd740c37932524337f8c5.JPG

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Interesting. I'd lean more on the Marti for accuracy.

Can you share so we can see the differences?

 

Ray

1971 Boss 351  

1972 Q code 4 speed convertible 

1971 Mustang Sportsroof  351-2V FMX 

1971 Hardtop (parts car)

1973 Mach 1 (parts car)

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Yes, that "5" on the Marti Report equates to a Wide Ratio 4-speed Transmission. Of course, it is possible that the previous owner replaced it with a Close Ratio ("6" Code) Transmission. The tag on the Wide Ratio Transmission for the 351 4V should be "RUG-AG." If it is a "Stock" Close Ratio Transmission for a 351 4V, the tag should be "RUG-E3" or "RUG-AV."

 

There are "ways" to pretty much determine what the rear end gear ratio is and whether or not it has a limited slip-type rear end without tearing it down. I am not going to possibly insult you by posting those methods up at this time as you may already be aware of them. If you are not and are interested, please advise.

 

Considering the rarity of your Mustang, I take it you are planning on restoring it to its former glory? Of course, here on this Site, we will try and support you whatever approach you decide to take.

 

BT

Do the RIGHT thing.

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Nice long list of options!

Mike AKA Ole Pony & Rare Pony
Our current Mustang garage/driveway
1973 Mustang Convert - Bought in 1974 - Still have it!
2004 Mach 1 Oxford White Auto, Bought Sept 06

20180127_082009.jpg

 

 

 

 

 

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Yes, that "5" on the Marti Report equates to a Wide Ratio 4-speed Transmission. Of course, it is possible that the previous owner replaced it with a Close Ratio ("6" Code) Transmission. The tag on the Wide Ratio Transmission for the 351 4V should be "RUG-AG." If it is a "Stock" Close Ratio Transmission for a 351 4V, the tag should be "RUG-E3" or "RUG-AV."

 

There are "ways" to pretty much determine what the rear end gear ratio is and whether or not it has a limited slip-type rear end without tearing it down. I am not going to possibly insult you by posting those methods up at this time as you may already be aware of them. If you are not and are interested, please advise.

 

Considering the rarity of your Mustang, I take it you are planning on restoring it to its former glory? Of course, here on this Site, we will try and support you whatever approach you decide to take.

 

BT

 

Thanks again BT,

 

I'm still in the process of getting to know this car. I did change the oil today and had a chance to look around under the car. Where would I be able to find the tranny tag codes? I do have access to an auto hobby shop on base with several lifts. I hope to get it on a lift this week some time. You mentioned "WAYS" to find out what the rear end gear ratio is. It is not possible for you to insult me on this subject, I'm a rookie, this is only my second 71-73 mustang... post away.

 

Unfortunately I did not get much in the way of history/receipts with the car. The dealership told me the car had a total restoration about 10 years ago. I don't think it was a total nut and bolt restoration, but whoever did it, did a good job on all the major components. The engine, tranny and rearend were all rebuilt. They added a chrome oil pan and chrome BOSS 351 valve covers. The suspension, exhaust and brakes were also redone. It has KYB gas adjust shocks on all 4 corners. The rear leaf springs are not new, but it does have coil over shocks in the rear. Everything works on the car, with the exception of the analog clock in the console. This car does not need a restoration at this point. Maybe before it goes to my son, he is 6 now, so I've got about 10 years to enjoy before all the work needs to be done. Thanks again for all your help and valuable advise.

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To determine rear end gear ratio, you first need to make sure that you have a limited slip-type rear end or not. The easiest way to do this is to see if you have two strips of rubber on the ground when you "take off" fast:). That is my polite way to say, do an "exhibition of speed." A functioning limited slip rear end should cause the tires to leave two "strips of rubber."

 

Once you have determined this, the following will apply:

 

You will probably need two people to do this "test."

 

1. If it is determined that you have an "Open" (read that Non Limited Slip) rearend, you can do the following:

 

jack up one side of the rear of the car.

 

Use a piece of chalk to put a vertical line at the top of one tire.

 

Also put a horizontal line on the drive shaft.

 

Rotate the tire one full revolution while counting the number of times the drive shaft rotates.

 

*The number of times the driveshaft rotates time 2 will be the approximate rear end gear ratio. For example, if the driveshaft rotates 1 1/4 times, that would equate to a 2.50:1 rear end.

 

2. For a limited slip rear end, it would be the same approach except you can jack up both sides of the rear of the car and will not have to multiply the drive shaft revolution by 2. For example, if the driveshaft rotates approximately 4 times, you probably have a 3:89 or 3:91 rear end gear.

 

3. Finally the way to know "for sure" is to pull the rear end and count the teeth on the ring gear and pinion. You would then divide the pinion number of teeth by the ring gear teeth to get the EXACT ratio.

 

That having been said, I believe the first method is least labor intensive and will put you in the "ball park."

 

Hope this helps.

 

BT

 

Edited to correct my "bad math." 1 1/4 on an open rear end would be a 2.50:1

Do the RIGHT thing.

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To determine rear end gear ratio, you first need to make sure that you have a limited slip-type rear end or not. The easiest way to do this is to see if you have two strips of rubber on the ground when you "take off" fast:). That is my polite way to say, do an "exhibition of speed." A functioning limited slip rear end should cause the tires to leave two "strips of rubber."

 

Once you have determined this, the following will apply:

 

You will probably need two people to do this "test."

 

1. If it is determined that you have an "Open" (read that Non Limited Slip) rearend, you can do the following:

 

jack up one side of the rear of the car.

 

Use a piece of chalk to put a vertical line at the top of one tire.

 

Also put a horizontal line on the drive shaft.

 

Rotate the tire one full revolution while counting the number of times the drive shaft rotates.

 

*The number of times the driveshaft rotates time 2 will be the approximate rear end gear ratio. For example, if the driveshaft rotates 1 1/4 times, that would equate to a 3.25:1 rear end.

 

2. For a limited slip rear end, it would be the same approach except you can jack up both sides of the rear of the car and will not have to multiply the drive shaft revolution by 2. For example, if the driveshaft rotates approximately 4 times, you probably have a 3:89 or 3:91 rear end gear.

 

3. Finally the way to know "for sure" is to pull the rear end and count the teeth on the ring gear and pinion. You would then divide the pinion number of teeth by the ring gear teeth to get the EXACT ratio.

 

That having been said, I believe the first method is least labor intensive and will put you in the "ball park."

 

Hope this helps.

 

BT

 

Thanks... sounds easy enough. I do appreciate your help. I'll let you know how it works out...

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  • 3 months later...

To determine rear end gear ratio, you first need to make sure that you have a limited slip-type rear end or not. The easiest way to do this is to see if you have two strips of rubber on the ground when you "take off" fast:). That is my polite way to say, do an "exhibition of speed." A functioning limited slip rear end should cause the tires to leave two "strips of rubber."

 

Once you have determined this, the following will apply:

 

You will probably need two people to do this "test."

 

1. If it is determined that you have an "Open" (read that Non Limited Slip) rearend, you can do the following:

 

jack up one side of the rear of the car.

 

Use a piece of chalk to put a vertical line at the top of one tire.

 

Also put a horizontal line on the drive shaft.

 

Rotate the tire one full revolution while counting the number of times the drive shaft rotates.

 

*The number of times the driveshaft rotates time 2 will be the approximate rear end gear ratio. For example, if the driveshaft rotates 1 1/4 times, that would equate to a 2.50:1 rear end.

 

2. For a limited slip rear end, it would be the same approach except you can jack up both sides of the rear of the car and will not have to multiply the drive shaft revolution by 2. For example, if the driveshaft rotates approximately 4 times, you probably have a 3:89 or 3:91 rear end gear.

 

3. Finally the way to know "for sure" is to pull the rear end and count the teeth on the ring gear and pinion. You would then divide the pinion number of teeth by the ring gear teeth to get the EXACT ratio.

 

That having been said, I believe the first method is least labor intensive and will put you in the "ball park."

 

Hope this helps.

 

BT

 

Edited to correct my "bad math." 1 1/4 on an open rear end would be a 2.50:1

 

I finally got around to checking out what rear end my car has. It is definitely a posi, 2 tire marks when putting down some rubber. I had almost 3 full rotations of the drive shaft, so it looks like the info the dealership gave me was correct, its a 2.91. I snapped some pixs while I was under the car. Got a few of the rear end and the tranny. Here is what the tranny says..."RF-D2AR-7006-CBW1" see the pix. How can I decode that so I can find out exactly what this tranny is?? Thanks...20121006_144651.thumb.jpg.d2cde008311e5f519cc576211d58ff91.jpg20121006_151255.thumb.jpg.89b810f55c82f08160b789bbf1fbacd4.jpg20121006_151319.thumb.jpg.4c601608188a597e994aaa1497e40a65.jpg20121006_151335.thumb.jpg.c46cf55c2219753ba8855c30945abb61.jpg

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To determine rear end gear ratio, you first need to make sure that you have a limited slip-type rear end or not. The easiest way to do this is to see if you have two strips of rubber on the ground when you "take off" fast:). That is my polite way to say, do an "exhibition of speed." A functioning limited slip rear end should cause the tires to leave two "strips of rubber."

 

Once you have determined this, the following will apply:

 

You will probably need two people to do this "test."

 

1. If it is determined that you have an "Open" (read that Non Limited Slip) rearend, you can do the following:

 

jack up one side of the rear of the car.

 

Use a piece of chalk to put a vertical line at the top of one tire.

 

Also put a horizontal line on the drive shaft.

 

Rotate the tire one full revolution while counting the number of times the drive shaft rotates.

 

*The number of times the driveshaft rotates time 2 will be the approximate rear end gear ratio. For example, if the driveshaft rotates 1 1/4 times, that would equate to a 2.50:1 rear end.

 

2. For a limited slip rear end, it would be the same approach except you can jack up both sides of the rear of the car and will not have to multiply the drive shaft revolution by 2. For example, if the driveshaft rotates approximately 4 times, you probably have a 3:89 or 3:91 rear end gear.

 

3. Finally the way to know "for sure" is to pull the rear end and count the teeth on the ring gear and pinion. You would then divide the pinion number of teeth by the ring gear teeth to get the EXACT ratio.

 

That having been said, I believe the first method is least labor intensive and will put you in the "ball park."

 

Hope this helps.

 

BT

 

Edited to correct my "bad math." 1 1/4 on an open rear end would be a 2.50:1

 

I finally got around to checking out what rear end my car has. It is definitely a posi, 2 tire marks when putting down some rubber. I had almost 3 full rotations of the drive shaft, so it looks like the info the dealership gave me was correct, its a 2.91. I snapped some pixs while I was under the car. Got a few of the rear end and the tranny. Here is what the tranny says..."RF-D2AR-7006-CBW1" see the pix. How can I decode that so I can find out exactly what this tranny is?? Thanks...

It would appear that you might have the original 4-speed transmission, based on the Marti Report and the casting number. D2AR-7006-CBW1 was utilized for 1972 and 1973 Mustangs equipped with the 351 4V motors. It is, as previously mentioned and/or inferred, a wide ratio (2.78 First Gear) Toploader transmission.

 

Again, considering your Marti Report and your having "laid down two strips of rubber", it appears that your rear end was changed at some point. Based on the report, your Mustang originally came with an "Open" rear end with a 3.25" rear end.

 

Hope this helps.

 

BT

Do the RIGHT thing.

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To determine rear end gear ratio, you first need to make sure that you have a limited slip-type rear end or not. The easiest way to do this is to see if you have two strips of rubber on the ground when you "take off" fast:). That is my polite way to say, do an "exhibition of speed." A functioning limited slip rear end should cause the tires to leave two "strips of rubber."

 

Once you have determined this, the following will apply:

 

You will probably need two people to do this "test."

 

1. If it is determined that you have an "Open" (read that Non Limited Slip) rearend, you can do the following:

 

jack up one side of the rear of the car.

 

Use a piece of chalk to put a vertical line at the top of one tire.

 

Also put a horizontal line on the drive shaft.

 

Rotate the tire one full revolution while counting the number of times the drive shaft rotates.

 

*The number of times the driveshaft rotates time 2 will be the approximate rear end gear ratio. For example, if the driveshaft rotates 1 1/4 times, that would equate to a 2.50:1 rear end.

 

2. For a limited slip rear end, it would be the same approach except you can jack up both sides of the rear of the car and will not have to multiply the drive shaft revolution by 2. For example, if the driveshaft rotates approximately 4 times, you probably have a 3:89 or 3:91 rear end gear.

 

3. Finally the way to know "for sure" is to pull the rear end and count the teeth on the ring gear and pinion. You would then divide the pinion number of teeth by the ring gear teeth to get the EXACT ratio.

 

That having been said, I believe the first method is least labor intensive and will put you in the "ball park."

 

Hope this helps.

 

BT

 

Edited to correct my "bad math." 1 1/4 on an open rear end would be a 2.50:1

 

I finally got around to checking out what rear end my car has. It is definitely a posi, 2 tire marks when putting down some rubber. I had almost 3 full rotations of the drive shaft, so it looks like the info the dealership gave me was correct, its a 2.91. I snapped some pixs while I was under the car. Got a few of the rear end and the tranny. Here is what the tranny says..."RF-D2AR-7006-CBW1" see the pix. How can I decode that so I can find out exactly what this tranny is?? Thanks...

It would appear that you might have the original 4-speed transmission, based on the Marti Report and the casting number. D2AR-7006-CBW1 was utilized for 1972 and 1973 Mustangs equipped with the 351 4V motors. It is, as previously mentioned and/or inferred, a wide ratio (2.78 First Gear) Toploader transmission.

 

Again, considering your Marti Report and your having "laid down two strips of rubber", it appears that your rear end was changed at some point. Based on the report, your Mustang originally came with an "Open" rear end with a 3.25" rear end.

 

Hope this helps.

 

BT

 

Sure does help. Thanks again. I'm sure there must be several links on this site about the pros and cons of a 3.25 vs a 2.91. I'll be searching...

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