I'm building a 72 Chevelle, changing from auto to manual.
I know auto trans but not much about 4 speeds. I want to go with a Muncie 4 speed. I plan on a big block with around 400 plus HP. I can and will change the rear gears to what will be best for my setup.

Would an M20 be best? Does the year built mean much?
I will be going to Corvettes at Carlisle soon and will be shopping for a trans so I need to know what to look for when buying, Casting numbers etc.
The 5 and 6 speeds are cost prohibitive for me so I'd like to stick to Muncie.

What should I look for when buying?
Thanks a lot
JZ

Get the M20 if you want quick launches from 1st along with a quick 1-2-3 gears. The M20 feels like a 6 spd F body car. Even with 3.55's with this tranny ratio (M20), it'll be like having 3.73-4.10's.

See www.gearzone.net but usually it's out to lunch so check some stuff out on my site http://ca.geocities.com/1970-z28@rogers.com/muncie.htm

IMHO it depnds on your grears, but with a 400hp Big Block you could go with any Muncie. If you decide on a M-20, go for the 1966 and newer with the 1 inch shaft. The cases that will have these are the 3885010 (1965-1967), the 3925660 (1968-1970), and the 3925661 (1970-1974). As far as I know, in these years, the M-20's have the same grear ratios. Which is different from the M21 and M22 trannys, which has a higher first gear. It's never a bad idea to put the Supercase on it. You can get this and any parts you need from Wally that post here. I've dealt with him and he knows his stuff.

Fred.

I'm building a 72 Chevelle, changing from auto to manual.
I know auto trans but not much about 4 speeds. I want to go with a Muncie 4 speed. I plan on a big block with around 400 plus HP. I can and will change the rear gears to what will be best for my setup.

Would an M20 be best? Does the year built mean much?
I will be going to Corvettes at Carlisle soon and will be shopping for a trans so I need to know what to look for when buying, Casting numbers etc.
The 5 and 6 speeds are cost prohibitive for me so I'd like to stick to Muncie.

What should I look for when buying?
Thanks a lot
JZ

Be real careful crusing around the fields of PA looking for a used Muncie. There is some real live junk out there and not very nice people selling it. If you want a good quality used unit, look up Larry Fischer of D&L Transmissions, he goes to the Corvette show, don't know about the other shows.

Hey Wally,

What is wrong with us people here in Pennsylvania? This is the wonderful Keystone State.

Regards, Jody

I knew this was coming.:)

Hey Wally,

What is wrong with us people here in Pennsylvania? This is the wonderful Keystone State.

Regards, Jody

Nothing wrong with the people in PA but most of the vendors and junk dealers are not from PA and if they are that does rule them them out selling junk.

Larry is from NY.

Junk is junk no matter who sells it or where you buy it, just be carful.

Thanks guys, yes I've been building Vettes and going to Carlisle for years and there are some pretty shady characters there but also some very reputable dealers.
I would buy from an established dealer or buy locally.
If anyone out there has a nice Muncie for sale let me know.
Thanks
JZ

viperjesse,

Our shop is about 1 1/2 hours from Carlisle. Even though we are from PA, we offer a 1 year warranty on all our transmissions! A speedometer calibration is included too.

We have correct rebuildable cores of Muncies for that '72 if you are interested in a local shop. We can also build a Muncie to your vehicle to replace your existing transmission. This saves you the least amount of changeover parts needed on your end. Or, we can build a Muncie to utilize a new clutch you might have lying around, driveshaft etc., whatever makes it easier on you.

We are also a distributor for Autogear if you want the new improved ratios they have to offer.

Regards, Jody

We bought a rebuild kit from Larry Fischer for our M21. The kit had bearings, synchros and the small stuff to do a rebuild. The price was right, quality was excellent and 3-4 years later the transmission is still working like new. A good guy to deal with.

just some things to look for
gm offered the muncie in a couple of diff ratios, 220 and 254 1st gear
the 220 was a close ratio trans, and the rear ratio was around 3:73 or lower
the 254 ratio was offered in 3:55 or higher ratio(im going on memory)
pontiac and others had diff trans(some borg warner) with lower 1st gear ratios
i would look for the more recent muncie, which used the fine splins input
and the larger output shaft(uses 400 trans style yoke) which everyone and their brother claims is an m22, but its not, and you cant convince them
i think it was around 70-71 this trans appeared
good luck

just some things to look for
gm offered the muncie in a couple of diff ratios, 220 and 254 1st gear
the 220 was a close ratio trans, and the rear ratio was around 3:73 or lower
the 254 ratio was offered in 3:55 or higher ratio(im going on memory)
pontiac and others had diff trans(some borg warner) with lower 1st gear ratios

The 2.54:1 was an early GM T10 ratio. The Muncie M20 was a 2.56:1 or 2:52:1 1st.

Even though "forcd ind" is correct, the '72 Chevelle would have had a 26 spline input and 32 spline output. I feel it is more cost effective and cheaper to buy a Muncie to replace the existing transmission. Unless you want the correct configuration Muncie.

Regards, Jody