MN12 in a 98 Firebird
09-05-2007, 12:53 PM
#3
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If you're referring to the GTO's transmission, it's not too difficult. You may need to change the tail-housing, but everything forward of that should bolt up just fine.
09-05-2007, 02:01 PM
#4
Originally Posted by _JB_
Not without a huge conversion process. Two totally different transmissions.
All you really have to do is swap out the shifter cup from your T56 into the M12 and it is a direct bolt in.
Galen
09-06-2007, 01:58 AM
#5
Originally Posted by Galen
Damn...now you tell me! I guess that since I just bolted mine up and have been driving it like that for over 10,000 miles I need to look into the "conversion process" to see what I had to have done wrong.
All you really have to do is swap out the shifter cup from your T56 into the M12 and it is a direct bolt in.
Galen
All you really have to do is swap out the shifter cup from your T56 into the M12 and it is a direct bolt in.
Galen
Last edited by _JB_; 09-06-2007 at 02:14 AM.
09-06-2007, 02:08 AM
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Originally Posted by Galen
Damn...now you tell me! I guess that since I just bolted mine up and have been driving it like that for over 10,000 miles I need to look into the "conversion process" to see what I had to have done wrong.
All you really have to do is swap out the shifter cup from your T56 into the M12 and it is a direct bolt in.
Galen
All you really have to do is swap out the shifter cup from your T56 into the M12 and it is a direct bolt in.
Galen
i guess you did lol serious is it any better?
09-06-2007, 08:22 AM
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Originally Posted by _JB_
I thought a MN12 tranny is out of a C5 Z06?
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09-06-2007, 08:53 AM
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it is a direct bolt in except for the shifter cup. You will have to take that off of you t56. I just ordered my mn12 and it will be going in next week. Cant wait 
09-06-2007, 09:56 AM
#9
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I've got one too. I created a chart that shows the equivalent gear ratios that you would have if you have 3.42 or 4.10 gears.
https://ls1tech.com/forums/manual-transmission/776536-comparison-f-body-gto-t-56-a.html
https://ls1tech.com/forums/manual-transmission/776536-comparison-f-body-gto-t-56-a.html
10-06-2007, 09:14 PM
#12
You can get one from me for $25 plus shipping. The GTO sits the shifter farther back and the GTO shifter is the only one you can use. With an F-Body shifter assembly you have more choice and all of my trans customers that have RX-7's use the F-Body shifters.
Thanks,
Amber
Thanks,
Amber
10-08-2007, 08:25 AM
#16
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The M12 (there's no 'N" in it's RPO) is a T56. It simply has different ratios and other improvements than the version found in the F-Body. It's price should be comparable to that of any other "non-built" T56.
10-10-2007, 01:42 AM
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How much does an M12 cost?
What are the advantages of having a M12 rather than a t-56?
10-10-2007, 08:47 AM
#18
A GTO trans is $2250 built compaired to an FB at $1950. Due to the blocker rings being triple cone in the GTO that is what drives the price up. As for putting one in, all you have to change is the shifter assembly over to the FB and it is a direct bolt in. The GTO is a 2.97 1st gear which alot of the road racers prefer. Most of the time the GTO will shift better and be smoother.
The only issue is that the GTO is alot harder to get since they stopped production. It normally takes me 4-6 weeks on average to gather all of the parts for one. I just got a few mainshafts yesterday. Since the gears are the same as the Z06 that tends not to be an issue most of the time.
Thanks,
Amber
The only issue is that the GTO is alot harder to get since they stopped production. It normally takes me 4-6 weeks on average to gather all of the parts for one. I just got a few mainshafts yesterday. Since the gears are the same as the Z06 that tends not to be an issue most of the time.
Thanks,
Amber
10-11-2007, 06:06 PM
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A GTO trans is $2250 built compaired to an FB at $1950. Due to the blocker rings being triple cone in the GTO that is what drives the price up. As for putting one in, all you have to change is the shifter assembly over to the FB and it is a direct bolt in. The GTO is a 2.97 1st gear which alot of the road racers prefer. Most of the time the GTO will shift better and be smoother.
The only issue is that the GTO is alot harder to get since they stopped production. It normally takes me 4-6 weeks on average to gather all of the parts for one. I just got a few mainshafts yesterday. Since the gears are the same as the Z06 that tends not to be an issue most of the time.
Thanks,
Amber
The only issue is that the GTO is alot harder to get since they stopped production. It normally takes me 4-6 weeks on average to gather all of the parts for one. I just got a few mainshafts yesterday. Since the gears are the same as the Z06 that tends not to be an issue most of the time.
Thanks,
Amber
10-11-2007, 06:23 PM
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