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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Swampyankee74 on December 11, 2022, 05:50:18 PM

Title: M21
Post by: Swampyankee74 on December 11, 2022, 05:50:18 PM
This weekend I purchased a muncie m21. My cab has a low tranny hump. The truck originally had a 3 speed manual.  Which is roughly the same size. The truck is all disassembled so it's hard for me to take any measurements. Has anyone put a muncie 4 speed in the low hump trucks? Is there any clearance issues?
Title: Re: M21
Post by: zieg85 on December 11, 2022, 07:16:28 PM
No clearance issues at all.  Same length and will take the same driveshaft yoke as the 3 speed manual
Title: Re: M21
Post by: Swampyankee74 on December 11, 2022, 08:20:07 PM
Thank you zieg! I thought it would work. But no way to measure. Cab is off frame and in a different building. Thank you very much
Title: Re: M21
Post by: zieg85 on January 27, 2023, 01:14:22 PM
Thank you zieg! I thought it would work. But no way to measure. Cab is off frame and in a different building. Thank you very much

You're welcome.  Word of advice.  If you have a high geared truck 2.56,.2.73, 3.08 or 3.42 with oversized tires starting out is not going to be fun.  Typically the M21/M22 transmissions used 3.73 rear or higher which wasn't an issue.  Rowing through 4 gears is fun. 
Title: Re: M21
Post by: Swampyankee74 on January 27, 2023, 01:26:49 PM
Yea the rear end is 3.73's. M21 is going behind a stroker that dynoed at 464hp. Tranny was built by a reputable shop outside of boston,, they say good for 800 hp (we'll see), mcleoud clutch, and a lake wood bellhousing. I'm a ways from driving it, but excited. Should be a fun toy.

Sent from my SM-S515DL using Tapatalk

Title: Re: M21
Post by: Swampyankee74 on April 13, 2023, 07:23:41 AM
Zieg, what shifter handle did you use on your muncie m? I was told a shifter handle for a chevy 2 nova was what I needed. That it will work with the bench seat?
Title: Re: M21
Post by: zieg85 on April 13, 2023, 07:53:37 PM
Zieg, what shifter handle did you use on your muncie m? I was told a shifter handle for a chevy 2 nova was what I needed. That it will work with the bench seat?

Trans was out of a Chevelle
Title: Re: M21
Post by: Swampyankee74 on April 13, 2023, 09:21:51 PM
Thank you zieg