Re: M21 vs T10
 

I was told that our was out of a '79 Z/28 and had the 2.64-1 first gear. It was the same length as the M20 we took out and we used the same driveshaft when putting the car back together.

Re: M21 vs T10
 

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those are good with like a 3;73 gear, I think there 2;88 first gear?? https://www.yenko.net/ubbthreads/imag...ins/3gears.gif

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Hopefully a 2:88 gear but I've seen them with a 3:42. Now you have to see if its a 904 steal case.

Re: M21 vs T10
 

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What ratio is your Super T10?

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Can I find out from the outside? https://www.yenko.net/ubbthreads/imag...lins/dunno.gif It's from an 80 Z28 allegedly, if that's a clue.

http://hphotos-snc3.fbcdn.net/hs479...._1745502_n.jpg


http://photos-f.ak.fbcdn.net/hphotos..._4100865_n.jpg

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How many rings/groves are on the input shaft?

Re: M21 vs T10
 

It looks like it has 6 rings on the input shaft. Should be a 3.42 first gear.

Re: M21 vs T10
 

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.......... Now you have to see if its a 904 steel case.

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This is one of the HEAVIEST transmissions I've ever carried (but it's been a while)

It seems to have rusted up almost overnight
http://photos-d.ak.fbcdn.net/hphotos..._8338292_n.jpg https://www.yenko.net/ubbthreads/imag...lins/dunno.gif

Re: M21 vs T10
 

Is this T10 a mutant, with the alum tail and the steel case?

Trans-man says T10 two inches longer at the case; ear to tail case end. The gears are out of the M21; could the length variable be the size of the rear spline ?

https://www.yenko.net/ubbthreads/imag...lins/dunno.gif

Re: M21 vs T10
 

[ QUOTE ]
Is this T10 a mutant, with the alum tail and the steel case?

Trans-man says T10 two inches longer at the case; ear to tail case end. The gears are out of the M21; could the length variable be the size of the rear spline ?

https://www.yenko.net/ubbthreads/imag...lins/dunno.gif

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I just measured a Muncie and a Super T10. There is a 1/2" difference in length from mounting flange to the rear seal. Your Super T10 is not a bastard. A lot of those transmissions came with iron case and aluminum tail shafts. I have owned bout 30 of them over the years.

-Matt

Re: M21 vs T10
 

Thanks Matt, can I get away with my original driveshaft with the 1/2" difference?

Re: M21 vs T10
 

According to the info i found, 6 grooves mean it has a 2.88 first gear, mine has 6 and i really hope is not a 3.42.
this is the ratios i found,
Number of ID Groves, 1st 2nd 3rd 4th
2, 2.43 1.61 1.23 1.00

3, 2.64 1.75 1.33 1.00

5, 3.42 2.28 1.46 1.00

6, 2.88 1.91 1.33 1.00

Re: M21 vs T10
 

Your number 5 and 6 are backwards Blade.

Chris- I think you could get away with your standard driveshaft.