T-5 or T-56 Manual Trans swap

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AuroraGirl

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I would say the M-21 could handle everything except heavy towing.
The 3.73 will ease the strain on the tranny anyway.
they were in Verres et al back in the day and can handle the HP and torque, and, as the C10 is much lighter in the rear, I would have no problem with hauling a bedful...... but, no sand and gravel, cus that would mess up the paint and wood floor.....
but it realistically could move a yard of gravel or rock just not the best suited(a 3/4 ton would be)

the reason I ask is this gives me a lot more options for a half ton 2wd square i hope to have in my future
 

bucket

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I had one years ago which I had planned to install into a '79 Z28, but other stuff got in the way and I sold it.

It seemed like a good idea at the time........

It was indeed a good idea and still is. It's a great all-around trans for a performance machine. I put one in my '86 Iroc and absolutely love it. My current '79 Camaro project is going together with a T56 as well. One day, I'd really like to put one in my big block C10.

An NV3500 is nice and can take some abuse, but it's certainly not 'sporty' trans. It's fairly truck-like when shifting and you probably won't care much for it after replacing an M21.

A T5 trans can be a lot of fun to drive... right up until you break it. Anything beyond 300lb/ft and 3500 lbs, it will not hold up well if you intend to have any fun.

A T56 is fun, and it holds up too. With the double overdrive, you can run a steep rear gear and get the economy you want. Supposedly with a carb, you kinda have to run at least a 3.73 or a 4.10 to make good use of 6th gear. I run a 3.23 in my car and it does fine, but it's also TPI.
 

AuroraGirl

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It was indeed a good idea and still is. It's a great all-around trans for a performance machine. I put one in my '86 Iroc and absolutely love it. My current '79 Camaro project is going together with a T56 as well. One day, I'd really like to put one in my big block C10.

An NV3500 is nice and can take some abuse, but it's certainly not 'sporty' trans. It's fairly truck-like when shifting and you probably won't care much for it after replacing an M21.

A T5 trans can be a lot of fun to drive... right up until you break it. Anything beyond 300lb/ft and 3500 lbs, it will not hold up well if you intend to have any fun.

A T56 is fun, and it holds up too. With the double overdrive, you can run a steep rear gear and get the economy you want. Supposedly with a carb, you kinda have to run at least a 3.73 or a 4.10 to make good use of 6th gear. I run a 3.23 in my car and it does fine, but it's also TPI.
Is an m21 better than m22
 

idahovette

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Depends on what you are going to use it for, but the correct answer is...NO. M22s are a heavier duty version of the M21 or wide ratio M20. Gears are cut on a straighter angle and they are noisy because of it. My Bride likes the noise and runs a lot in 2nd and 3rd gear.
 

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Depends on what you are going to use it for, but the correct answer is...NO. M22s are a heavier duty version of the M21 or wide ratio M20. Gears are cut on a straighter angle and they are noisy because of it. My Bride likes the noise and runs a lot in 2nd and 3rd gear.
I like the sound of a Rock Crusher too.
 

idahovette

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Yeah @WFO, people who don't know the "rock crushers" always ask me "what's wrong with your car, it's so noisy". I just tell them the transmission is going out!!...LOL.. they don't have a clue!... The people that know just give a thumbs up
 

Ronno6

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It was indeed a good idea and still is. It's a great all-around trans for a performance machine. I put one in my '86 Iroc and absolutely love it. My current '79 Camaro project is going together with a T56 as well. One day, I'd really like to put one in my big block C10.

An NV3500 is nice and can take some abuse, but it's certainly not 'sporty' trans. It's fairly truck-like when shifting and you probably won't care much for it after replacing an M21.

A T5 trans can be a lot of fun to drive... right up until you break it. Anything beyond 300lb/ft and 3500 lbs, it will not hold up well if you intend to have any fun.

A T56 is fun, and it holds up too. With the double overdrive, you can run a steep rear gear and get the economy you want. Supposedly with a carb, you kinda have to run at least a 3.73 or a 4.10 to make good use of 6th gear. I run a 3.23 in my car and it does fine, but it's also TPI.

On a side note, I installed kevlar composite rear leaf springs and a transverse kevlar composite spring on the front with tubular control arms and stiffer shocks all around....... It was kinda like riding on a brick, but you could slide corners with practically zero lean..... Suspension parts from what was then Vette products and brakes in St. Pete Fl..... stock 350 w/T10 BW
 

Ronno6

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An NV3500 is nice and can take some abuse, but it's certainly not 'sporty' trans. It's fairly truck-like when shifting and you probably won't care much for it after replacing an M21.

A T5 trans can be a lot of fun to drive... right up until you break it. Anything beyond 300lb/ft and 3500 lbs, it will not hold up well if you intend to have any fun.

Tremec has TKO and TKX 5-speed trannys good to 600 lbft (ftlb?) of torque, and a reasonable 1st gear 2.75 or something of the sort.....close ratio anyway.....
 
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bucket

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On a side note, I installed kevlar composite rear leaf springs and a transverse kevlar composite spring on the front with tubular control arms and stiffer shocks all around....... It was kinda like riding on a brick, but you could slide corners with practically zero lean..... Suspension parts from what was then Vette products and brakes in St. Pete Fl..... stock 350 w/T10 BW

I've never known of anyone that installed that transverse front spring kit. I also didn't realize they were based in St Pete.

Tremec has TKO and TKX 5-speed trannys good to 600 lbft (ftlb?) of torque, and a reasonable 1st gear 2.75 or something of the sort.....close ratio anyway.....

Oh. Cheapass me thought we were only talking about stock stuff, lol.
 

Ronno6

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I've never known of anyone that installed that transverse front spring kit. I also didn't realize they were based in St Pete.

They used to was back in the 90's..........
Dunno if they are even still around.

As for the transverse front spring....you had to cur openings in the cross member for the spring to pass thru, and plates to guide the spring and provide fulcrum points.
It was pretty slick.
Heavier f&r sway bars were also part of the package.
Great kit, and lt shaved probably 250# off the weight.
 

dsteelejr

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So is an m21 more “street able” than a sm465 and obviously an extra gear than the trans the lighter manuals came ?

Ehat kind of mpg ? Is it stil able to do lighter duty truck stuff or too anemic?

The M-21 and its sister model M-22 rock crusher was used in muscle cars, often paired with a 4.10 or 4.56 rear end. First gear in the M-21 is 2.20. I don't see it as doing much good in a pick up truck unless its a light weight C10 and you don't plan on doing much other than driving it around like car.
 

AuroraGirl

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The M-21 and its sister model M-22 rock crusher was used in muscle cars, often paired with a 4.10 or 4.56 rear end. First gear in the M-21 is 2.20. I don't see it as doing much good in a pick up truck unless its a light weight C10 and you don't plan on doing much other than driving it around like car.
Can it be easily identified externally? Idk which mine is because the 76 nova came with both factory and that’s the only reason I know it’s one
 

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