I have a 4 speed car and would like nothing more then to get the weak old saginaw out of the pictures. There are a couple people with muncie's for sale locally that seem to be a good price. My question is A) will it bolt right in B) how much abuse will an M21 handle?
Manual transmission differences
- Thread starter blumonte
- Start date
my brother went from a saggy 4 speed to a m21 and i think it was pretty straight forward, same d-shaft bolted right up to the same bellhousing but he had to modify the linkage. As far as strength goes he has a blown 355 and he is very very hard on it and it just loves it hasn't had any problems thus far
Everything will bolt up, I'm not positive on the driveshaft though. How much power do you think you're making? I have a 3-speed Saginaw in mine right now behind a 350-375hp 350 (~400 ft. lbs. of torque), and I didn't have a single problem with it all last summer. I've read both ways with Saginaws... some hold up great, some people go through 'em like water. A large part is how you use them. Hammer/power shift all the time and don't expect it to live long, don't shift it hard, drop the clutch, etc. and it should be ok. I drove mine closer to the latter (a couple quick shifts, but not many), but that doesn't mean I was easy on the gas 
BTW, I've also heard the same thing about Muncies/T10s. Also be wary of the gear ratio set your transmission has, it can affect the attitude your car has from a stop. You can tell by looking at the grooves that run around the input shaft perpendicular to the splines.
http://maliburacing.com/forum/viewtopic.php?f=7&t=67662&p=596699
BTW, I've also heard the same thing about Muncies/T10s. Also be wary of the gear ratio set your transmission has, it can affect the attitude your car has from a stop. You can tell by looking at the grooves that run around the input shaft perpendicular to the splines.http://maliburacing.com/forum/viewtopic.php?f=7&t=67662&p=596699
Here's some info on Muncies
http://www.5speeds.com/muncie2.htm
I've had a M21 close ratio in my since I've owned it and about5 years before that..apx 15 yrs in total.. That trans has outlasted the past owner engine .. and the factory 10 bolt... I'm NOT affaid to dump the clutch all day every day with it...
my 2 cents
http://www.5speeds.com/muncie2.htm
I've had a M21 close ratio in my since I've owned it and about5 years before that..apx 15 yrs in total.. That trans has outlasted the past owner engine .. and the factory 10 bolt... I'm NOT affaid to dump the clutch all day every day with it...
my 2 cents
The Muncie is a direct swap for the Saginaw, but you will need a new shifter or shifter mount if you already have a Hurst shifter. All M21/M2's are close ratio. All M20's are wide ratio. There are 2 different gear sets for the M20. One has a 2.56 1st, the other has a 2.52. The 2.56 is from the 2 older versions. M20's were used by GM on 3.70 & numerically lower rear end ratios. The M21/22 was used on 3.90 & higher. A stock Muncie has higher torque capacity rating than the strongest aftermarket T10.
Tommy
Tommy
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