Momar

I know that the 93 transmissions are rated at lower power, but what is the reason. I have heard that it was because of the first gear ration being so steep but do not know if this is true. If that is the case would the G92 tranny with the 2.97 first be between the 2 ratings? Also, I have seen some people push a lot more power through these than rated. In the real world how much difference is there between the 2. I will be using a G92 T56 out of a 93 Z28 in my 85 T/A either way, I would just kind of like to know. It has a centerforce clutch and B&M ripper shifter fyi. I plan to put it behind my 350 and then within a few months put a 383 in front of it. With my 350 I am running with some of the stock LS1's already. I beat a LS1 z28 from a 40 mph roll up to about 105 but it was close the whole way.

Ben

Momar

ttt

IDOXLR8

The reason behind the lower hp/tq rating is due to the steeper gears in the transmission. I am currently running an M28 (3.36 1st gear) and pushing 705 rwhp with no problems. When the time comes for a rebuild I will 300M all the internals.

Momar

Can you do that to used parts? What kind of times have you ran with that much power by the way.

Thanks

Ben

IDOXLR8

I have not been to the track so I am not sure. Are you asking whether or not you can 300M used parts? The answer is yes but in my opinion I would buy new parts.

Fastbird93

If you were fortunate enough to get an M29 tranny in 93, then your power ratings go up. The M28 was the standard F-Body six speed, but the M29 went in to the early production models. It was a tranny originally destined for a Viper, but GM bought a bunch off of Chrysler/Dodge because Borg Warner didn't have the regular spec F-Body M6's ready yet. I believe the M29 was rated to 450 lb-ft of torque. Someone chime in here.

KCFormula

M28- 350ft/lb
M29-400ft/lb
MN6-450-ft/lb


IMHO, They are all about the same. I am sure the only reason they rate the M28 so low is because of the thin teeth for the 1st gear. I have never heard of any M28 breaking due to this, so I wouldn't worry about it. I would enjoy your good 1st gear while all the LS1 guys whine about how tall their 1st gear is. Besides it allows you to run a 28" tire with not as agressive of a rear end ratio!

Momar

I have a M29 not a M28. I was just wondering how the strenght was. Sounds like it is pretty decent.

Ben

gsf_87iroc

I am new here and have a question.

I just bought a T56 at a swap meet for my IROC. The guy said it was a 93 or 94. I checked it and the date tag appears to be a 94(per a post I saw at paceparts)...but the 6th gear appears to be a 93.

If it's a 93, is there a way on the trans to tell if it's a M28, M29, or MN6? I have no access to the car it came from.

Also, is there a good website with date code info on these trans's?

Thanks,

Momar

The only way I was able to find if you dont have access to the car it came out of is to put it in first gear and see how many times you have to turn the input shaft to get the output to turn one time. m28 will be about 3.36 and the m29 should be 2.97. So whichever you come out closest to. On mine it comes turns just under 3 times so that means it would be the m29. If it spun about 3 1/3 times it would be an m28

Ben