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Gear ratio 2.87 to 1. The 1/4 bolt straps are definitely 1330 u-joints. A 1350 has 1.188 cap od while the 1330 is 1.062. Mike is definitely the man you want to talk to. If you are considering upgrades I have a 12 bolt conversion thread with pictures of new parts. I believe the first u-joint cap pictures will fit your half shafts. The outers would need the holes enlarged to a 5/16 thread which I would advise anyone to do if they are willing. They can be made for 1/4 bolts but I think most would rather have the larger fastener for strength.
If you need Mike's contact information please feel free to send pm and I will get it to you.
Dave
Gear ratio 2.87 to 1. The 1/4 bolt straps are definitely 1330 u-joints. A 1350 has 1.188 cap od while the 1330 is 1.062. Mike is definitely the man you want to talk to. If you are considering upgrades I have a 12 bolt conversion thread with pictures of new parts. I believe the first u-joint cap pictures will fit your half shafts. The outers would need the holes enlarged to a 5/16 thread which I would advise anyone to do if they are willing. They can be made for 1/4 bolts but I think most would rather have the larger fastener for strength.
If you need Mike's contact information please feel free to send pm and I will get it to you.
Dave
Thanks Dave, how did you ID the gear to be a 2.87, i thought they were 3.07. What does the 2.87 mean in terms of LS1, and gearbox choices ?
What do you mean by "I believe the first u-joint cap pictures will fit your half shafts. "
"The outers would need the holes enlarged to a 5/16 thread which I would advise anyone to do if they are willing."
Can i get new outer shells instead of drilling the 1/4" ones or are they the same size but just smaller bolts
Wonder why i have two different size u joint bolts ?
The 43 and 15 should be the number of teeth on the ring and pinion. You divide the ring teeth (43) by the pinion teeth which gives you the ratio. i believe 82 vettes came with 700r4 transmission which is how the 2.87 gear works. You can search for thread labeled 12 bolt conversion if you want to see the pictures. I know Mike would be willing to upgrade the threads for you if you are not comfortable doing it. Here is 1 picture to give you idea of difference. Making a part for the stock thread is also possible.
Dave
The 43 and 15 should be the number of teeth on the ring and pinion. You divide the ring teeth (43) by the pinion teeth which gives you the ratio. i believe 82 vettes came with 700r4 transmission which is how the 2.87 gear works. You can search for thread labeled 12 bolt conversion if you want to see the pictures. I know Mike would be willing to upgrade the threads for you if you are not comfortable doing it. Here is 1 picture to give you idea of difference. Making a part for the stock thread is also possible.
Dave
Ok great thanks for telling me how to work it out.
I found it, i have a TH350C 1980 vette, not sure why i now have a 82 gear in it.
JC Turbo Hydra-Matic 350 with 305 California Engine
Whats the best trans and gear for LS engine swaps ?
Thanks again Dave.
Can we buy these new straps and i would need them for the hub side right since i have 8mm ones on the diff side ?
You need to decide which transmission you plan on using so you can pick a reasonable RPM on the freeway.
No point in having a 2.87 and a TKO with a .64 OD
What you have now should have been about 2500 RPM @ 70MPH with the Turbo 350.
With everything the same but with a .64 OD you would be at 1600 RPM. I'd say even with a LS1 conversion that may be a low for the freeway.
You need to decide which transmission you plan on using so you can pick a reasonable RPM on the freeway.
No point in having a 2.87 and a TKO with a .64 OD
What you have now should have been about 2500 RPM @ 70MPH with the Turbo 350.
With everything the same but with a .64 OD you would be at 1600 RPM. I'd say even with a LS1 conversion that may be a low for the freeway.
Im not certain how to use that link yet as ui have not choosedn thwat tyres i want yet.
So lets say im going for a Gen 2 or 3 LS1 and 4L60E , what is the best gear ratio i should get. And where is the best place to buy it, what exactly do i need to replace along side the gear ?
I im a delimma, i either leave the diff as is and dont even fix it, just run it until it dies and then get a 1979 stronger diff with better half shafts ... Being in Australia the postage kills me trying to get these parts.
You need to decide which transmission you plan on using so you can pick a reasonable RPM on the freeway.
No point in having a 2.87 and a TKO with a .64 OD
What you have now should have been about 2500 RPM @ 70MPH with the Turbo 350.
With everything the same but with a .64 OD you would be at 1600 RPM. I'd say even with a LS1 conversion that may be a low for the freeway.
So it sounds to me that You have 1980 Automatic 1330 Axel Flanges. And then You have a 82 Pumpkin with 1350 Yokes. So the question is do You have the 80 or 82 1/2 shafts. On one side or another You must have Conversion U-Joints that are 1350 and 1330. In other words, somebody switched out the the Pumpkin with an 82 and they used Conversion U-Joints to make it work.
So it sounds to me that You have 1980 Automatic 1330 Axel Flanges. And then You have a 82 Pumpkin with 1350 Yokes. So the question is do You have the 80 or 82 1/2 shafts. On one side or another You must have Conversion U-Joints that are 1350 and 1330. In other words, somebody switched out the the Pumpkin with an 82 and they used Conversion U-Joints to make it work.
Yes your onto something there.
The U joint attached to the trailing arms have end caps measuring around 25mm for both half shaft and wheel hub.
The U joint attached to the diff side has end caps 30mm wide and the caps on the half shafts are 25mm.
So only the yokes are 30mm using the large straps.
I cant find an answer on the best gear to use with LS1 and the 4L60E. Im not sure what wheels and tyres to run. Im not doing drags, just hwy cursing and a little spirited driving in the mountains.
Interesting article. Completely inaccurate but good pictures.
80-82 Dana D44 failures were common in the mid eighties. Lots of bad castings and machining. Most likely the original diff failed and a used 82 diff was installed.
80-81 with automatics got the 1330 u-joints with 1/4 in. bolts in the half shafts. The 4 speeds got the 1350 u-joints with 5/16 bolts. In 1982 there were no 4 speed vettes built and since it was the end of the run they used up the 4 speed stub axles, halfshafts and flanges.
The clutch plate failure is common on the 80-82. This is a design flaw that was corrected in 1985. The proper fix for an 80-82 is to install the 85-96 carrier.
R6n350GT, your clutches are damaged and so is the carrier. Replacing just the retainers won't do any good. You also have wear on the stub axles and cross shaft.
Mike
Interesting article. Completely inaccurate but good pictures.
80-82 Dana D44 failures were common in the mid eighties. Lots of bad castings and machining. Most likely the original diff failed and a used 82 diff was installed.
80-81 with automatics got the 1330 u-joints with 1/4 in. bolts in the half shafts. The 4 speeds got the 1350 u-joints with 5/16 bolts. In 1982 there were no 4 speed vettes built and since it was the end of the run they used up the 4 speed stub axles, halfshafts and flanges.
The clutch plate failure is common on the 80-82. This is a design flaw that was corrected in 1985. The proper fix for an 80-82 is to install the 85-96 carrier.
R6n350GT, your clutches are damaged and so is the carrier. Replacing just the retainers won't do any good. You also have wear on the stub axles and cross shaft.
Mike
Thanks Mike, so i didnt want to spend too much on this diff until i found better options.
Are the stub axles 100% worn or just likely to be
If rebuilding the 1980 diff are these parts what i need ?
Dana Spicer 41232 TRAC LOK DIFFERENTIAL BARE CASE fits DANA 44 rear end 1985 to 1996 Chevrolet Corvette (this doesnt use keepers like mine that broke?)
- But it says i cant use my 2.87 gear ...
Dana Spicer 707018X Positraction clutch plate kit for DANA 44 Trac Lok 1985 to 1996 CORVETTE TRACK LOCK
05-29-2017, 04:16 AM
Dana 44 in a 1980 but has 82 gear inside and mix
