muncie transmission conversion

[Ricks1971]

do any of you guys have pics of a M21 Muncie conversion?

[demian5]

I considered one when contemplating getting turbo 350 rebuilt. I have the trans and bellhousing on a shelf.

[Astro-Balls]

I would like to put a M21 in my C20, will it bolt right up or will the drive shaft length need to be changed?
Have a SM465 now.

[Ricks1971]

I was told the SM465 bellhousing won't work

[geezer#99]

Originally Posted by Ricks1971

I was told the SM465 bellhousing won't work

Yes it will.
You need an input bearing hole spacer if the bearing housing is 5 1/8 inches.

https://www.advanceadapters.com/prod...-down-to-4686/

The hardest part is shifter location. It’ll sit almost under the seat. You’ll need a modified bench seat shifter.

[406flyfish]

What ^ he said. The bell housing works off a sm265. The shifter ends up being at the edge of the seat. Also the hurst shifter that says it will fit does not. Not even close. The driveshaft also needs to be shortened.

[geezer#99]

If you modify a bench seat shifter handle like this, it will work.
https://core-shifters.com/products/h...-bel-air-nomad

[70 shorty]

wouldn't a M21 put the shifter in the same place as a 3 speed floor shifter? I have a Hurst 3 speed floor shifter in mine with the bench seat, and it doesn't have the bend at the bottom of the one shown above. Yes, it is close but it works. For a long time, I've wanted to put a Tremec 5 speed in my Corvette and put the Corvette's 4 speed in the truck.

[special-K]

I don't consider this a conversion, unless you are converting from automatic to manual. To go from factory 3spd to M20-22 is purely bolt-in, other than the hole in the floor for the shifter. Although, I do prefer using a car bell housing and automatic crossmember for a tail shaft mounting arrangement.

[geezer#99]

Originally Posted by 70 shorty

wouldn't a M21 put the shifter in the same place as a 3 speed floor shifter.

It might!
You’ve got both.
Measure them and post the numbers.

[SIXTY9]

I have ran a M20 Muncie in my 69 for a long time. I used bucket seats and bench seats with it. The shifter I used was a Hurst Competition Plus.The shifter handle number is Hurst 4331. Here is a picture of it.

[LockDoc]

-
I had one in my '67 stepper many years ago. Mine was originally a column shift three speed so I just used the column shifter for the four gears and used a choke cable for reverse. Worked good and my son drove it that way when he started driving it to school.....

LockDoc

[88fordf150]

Muncie 4 speed in my truck.

[special-K]

Originally Posted by SIXTY9

I have ran a M20 Muncie in my 69 for a long time. I used bucket seats and bench seats with it. The shifter I used was a Hurst Competition Plus.The shifter handle number is Hurst 4331. Here is a picture of it.

Thanks for the model#. We used to use the 55-57 bench seat shifter, but I know they offer a truck-specific shifter now. I have buddy buckets for my '67 that I get an M22.

[Ricks1971]

thanks for the pic

[Markuli]

Hurst sells two kinds of shifter kits for M20,M21 and M22's - Make sure you buy the one that has the two- bolt connection of the handle to the linkage. I bought a shifter that some claimed would fit and I ended up having to modify it because it was welded to the linkage. Would have been a lot easier to just unbolt the lever and bolt up a new one.

[nikwho]

Ive found myself doing this swap in my '68 GMC. My truck was originally a 327/4 speed truck, but had been swapped to a th-350. Now Ive pit a big block in it and swapping to a M21, or M22. Still trying to source a good transmission. Im also switching to bucket seats at the same, so I hope to have fewer issues with shifter location.

What is the best place to source a clutch & brake pedal assembly?

[geezer#99]

Originally Posted by nikwho

Ive found myself doing this swap in my '68 GMC. My truck was originally a 327/4 speed truck, but had been swapped to a th-350. Now Ive pit a big block in it and swapping to a M21, or M22. Still trying to source a good transmission. Im also switching to bucket seats at the same, so I hope to have fewer issues with shifter location.

What is the best place to source a clutch & brake pedal assembly?

Pedals?

https://www.4speedconversions.com/72_truck_pedals.html

Tranny?

http://www.garagemotorsports.com/muncie.htm

[JudgeUnderwoodHammer]

Originally Posted by Astro-Balls

I would like to put a M21 in my C20, will it bolt right up or will the drive shaft length need to be changed?
Have a SM465 now.

I have an M20 in my 67 C10. I used the original 350 turbo driveshaft, the slip yokes are the same. The SM465 is a fixed yoke transmission. Therefore your driveshaft would not work you probably already know this. I am thinking the M20-M22's are a little longer than the SM465. I could be wrong. As mentioned above I too used a car bell housing and an automatic transmission crossmember.

[Markuli]

Originally Posted by JudgeUnderwoodHammer

I have an M20 in my 67 C10. I used the original 350 turbo driveshaft, the slip yokes are the same. The SM465 is a fixed yoke transmission. Therefore your driveshaft would not work you probably already know this. I am thinking the M20-M22's are a little longer than the SM465. I could be wrong. As mentioned above I too used a car bell housing and an automatic transmission crossmember.

The "car" Muncie's are longer. You'd need to shorten your driveshaft.

[nikwho]

How does the length of a "car" Muncie compare to the length of a TH-350?

[Mike C]

Originally Posted by nikwho

How does the length of a "car" Muncie compare to the length of a TH-350?

They are pretty much the same.