Munice 4sp or Super t10 Towing camper ok?

[gearheadperkins]

Hey guys I am about to swap in a new 4sp in my 72. it will either be a Munice M21 -m22 or a super t10 .. I have a mild 400sb.. I will not be towing anything over a small camper or bass boat (say less thank 5k).. will this tranny hold up under normal driving.. i want to keep it a 4sp ...

[Toms67]

If you're running 373 gears or higher. You should be OK. The M 21 is what I am running. First gear is a little steeper. It is a close ratio tranny. Do some searches and you should find more info. Good luck.

[gearheadperkins]

I have 3.73's .. Thanks for the info I just didn't want to put to much pressure towing on the tranny. Do you tow with yours alot ?

[Steeveedee]

I personally would recommend a wide-ratio 4 speed so that you have decent off the line torque multiplication. That said, if you can find an M-22 you can afford, I highly doubt you will break it, given the number of 454 Chevelles that have had a zillion high power shifts thrown at them. Noisy as all get-out, though. I don't remember if you can get them with wide or close ratio gearing, though. I think they were all close ratio, but people are always making new gears. My knowledge in this area is 40 years old, when it comes to specifics.

[oldertruckfan]

either trans will be fine. I ran a super T10 back in the day, hooked to a 427 with no issues. your biggest issue may well be finding one

[Mike C]

I broke my 2.64 1st gear T-10 in my Camaro 2 years ago due to stupidity.... I replaced it with a 2.42 first and miss the lower first gear. A lot. My car has 4.10 gears and 29" tall tires.

IMO, you will be MOST unhappy with an M21 and its 2.21 first gear in a truck. Personally, if you want a street/strip style truck I would do a T56 swap. Then you could run 4.56 gears which to me would be an excellent combo with the .5 6th gear. But if you want a truck/truck then the SM465 would be my choice.

For utility, you just can't beat the granny first. My '79 CJ-5 has 3.54 gears and a 2.97 1st gear and 33" tall tires. And to pull my bass-boat up the ramp I have to use low range. Which with the Dana 20 means I STILL have last gear then first high range in an SM465.

[geezer#99]

Rebuilt's are available.
The t 10's work better if you have higher rear gears like 3.08's.

The m21 and m22 having 2.20 first gear like a 3.73 gear but have been run with 2.73 rear gears. My first 70 chevelle LS6 had a m22 with a 2.73 gear from the factory with a trailer towing package on it. THe original owner like to pull his boat to the lake and preferred to do the 90 miles at speed.

Trans available here.
http://www.garagemotorsports.com/muncie.htm

And check out Autogear for wide ratio muncies.
http://www.autogear.net/motorsports/

[Toms67]

I towed years ago with The M 21. Didn't have any problem. As long as you don't tow over capacity. I haven't towed with this transmission yet. Still putting it back together. The truck that is.

[Ken B]

Originally Posted by Mike C

I broke my 2.64 1st gear T-10 in my Camaro 2 years ago due to stupidity.... I replaced it with a 2.42 first and miss the lower first gear. A lot. My car has 4.10 gears and 29" tall tires.

IMO, you will be MOST unhappy with an M21 and its 2.21 first gear in a truck. Personally, if you want a street/strip style truck I would do a T56 swap. Then you could run 4.56 gears which to me would be an excellent combo with the .5 6th gear. But if you want a truck/truck then the SM465 would be my choice.

For utility, you just can't beat the granny first. My '79 CJ-5 has 3.54 gears and a 2.97 1st gear and 33" tall tires. And to pull my bass-boat up the ramp I have to use low range. Which with the Dana 20 means I STILL have last gear then first high range in an SM465.

I agree with this statement 100% Having had a 69 SS Chevelle with a healthy 427 in it with an M-22 4 speed and 3.55's out back I can tell you first hand that your truck will be very lame towing a camper with that setup. Once I put 4.11's out back it was so much happier...

[Ken B]

Originally Posted by geezer#99

Rebuilt's are available.
The t 10's work better if you have higher rear gears like 3.08's.

The m21 and m22 having 2.20 first gear like a 3.73 gear but have been run with 2.73 rear gears. My first 70 chevelle LS6 had a m22 with a 2.73 gear from the factory with a trailer towing package on it. THe original owner like to pull his boat to the lake and preferred to do the 90 miles at speed.

Trans available here.
http://www.garagemotorsports.com/muncie.htm

And check out Autogear for wide ratio muncies.
http://www.autogear.net/motorsports/

I'm not doubting anything that you say but with the cam that an LS6 came with, an M-22 4 speed Chevelle with 2.73 gears out back sounds like anything BUT a Chevelle equipped with a tow package. I bet some clutches were burnt up at the boat ramp.

[special-K]

People used to tow all the time with the 3spds. Any of these car transmissions have a better 1st for towing/hauling. My little '67 will have a car 4spd, hitch, lowered suspension that can carry, and a bed that will get scratched.

[gearheadperkins]

Wow. I really appreciate all the responses. I look forward to this swap in very near future. Can't wait to make this my daily and tow pig

[Mike C]

Originally Posted by special-K

People used to tow all the time with the 3spds. Any of these car transmissions have a better 1st for towing/hauling. My little '67 will have a car 4spd, hitch, lowered suspension that can carry, and a bed that will get scratched.

I disagree Tim, and not according to this chart. Most of the 3 speeds had a MUCH lower first gear than the aluminum cased car 4 speeds. I would guess the truck ones were the 3.5 first gear. And they usually had 3.73 gears.

3.73 was the smallest numeric ratio you could get from GM factory with the 2.21 first gear M21/M22 and 4.10 were better. 4.56 more so. It was built to be a road race transmission and still can lay claim to the closest ratio factory 4 speed ever made. But that's not worth a flip on the street.

I don't have much experience with GM 3 speeds, but LOTS with the jeep 3 speeds. And even with 4.88 gears in my '44 and 5.38 in my '52. They need more gear except at speed. Which you don't really want to be at. Terrifying!

http://www.roadkillcustoms.com/hot-r...#axzz4jYTMo8Qc

[geezer#99]

Originally Posted by Mike C

3.73 was the smallest numeric ratio you could get from GM factory with the 2.21 first gear M21/M22

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Not true!
I had the build sheet for both my 70 chevelles. The LS6 had an m22 with factory 2.73 gears and the L34 had an m21 with factory 3.31's.