C3 Vette Registry - The Best Resource on the Net for C3 Vettes! C3 Vette
Forums -> C3 Driveline Components
Not Logged In! Login or Register!  Users Online: 21 / Help 
Features  Find C3 Parts on ebay in only 2 or 3 clicks!  | Add YOUR C3 to the Registry

Supporting Vendors
Volunteer Vette Products
CorvetteClothing.com
Mid America Motorworks
VetteBookStore.com
Bair's Corvettes

C3 of the Month
None Current
Enter Yours Today!
Online C3 Show
13
C3s are Registered

Vanity Plates
LOWBROW
Lowbrowser
Featured Links
Chevrolet Corvette Restoration Guide


Buy Now
Kindle
Kindle


Corvette Masterpieces: Dream Cars You'd Love to Own (Hardcover)
Corvette Masterpieces: Dream Cars You'd Love to Own (Hardcover)


Motor Trend - $5 for 12 issues.
Motor Trend
Only $5 for 12 issues.


Corvette 50th Anniversary
Corvette 50th Anniversary



| Hide Signatures and Profile Pics

 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
8/24/10 7:12am - Original Message: 'M20,21,or 22'
manchestershark Lifetime Member
Lifetime Member
- Send Private Message


Equinunk, PA - USA

Vette(s):
1972 conv, 4-speed, 350, 200hp, numbers match, rally wheels, war bonnett yellow w/white top. good condition, nice driver.

Joined: 10/31/2007
Posts: 1901
 I have a base car. 72 350. The transmission has/is 11inch fine spline aluminum case. The tank sticker says BASE for transmission. The question I have is what one is it? 20,or 21. I doubt it is a 22.  Close or wide ratio? It seems high on bottom end, not much pizzaz. Top end is good and gets in the area of 18 MPG.    IDEAS?    THANKS   Mark
 Reply Reply  Quote Reply w/Quote
 
Support C3VR!
Suport our advertisers
8/24/10 7:23am - Reply: 'M20,21,or 22'
Adams' Apple Lifetime Member
Lifetime Member
Moderator
- Send Private Message


Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19459
"Base" or standard equipment 4 speeds were the wide ratio, M20 transmissions. They do have a better 1st gear ratio than the M21....2:56 compared to a 2:20.

____________________________________
Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
 Reply Reply  Quote Reply w/Quote
8/24/10 9:12am - Reply: 'M20,21,or 22'
Gunslinger
Former Member
- Send Private Message


Frederick, MD - USA

Vette(s):
1969 convertible L71 427/435 4-speed black interior

Joined: 9/8/2003
Posts: 3398
My '69 has the M21 close ratio...very little spread in gearing at all...even in slow to moderate driving I'm banging gears fast.  Bang, bang, bang and I'm in 4th.  Actually, unless I'm on an upward slope, the car doesn't really need 1st and 2nd gear.  Starting out in 3rd is no trouble at all.

____________________________________
Poet...Mystic...Soldier of Fortune. As always...self-absorbed, adversarial, c o c k y and in general a malcontent.

Click image for larger pic
 Reply Reply  Quote Reply w/Quote
8/24/10 10:40am - Reply: 'M20,21,or 22'
cthulhu Lifetime Member
Lifetime Member
- Send Private Message


Hot Springs, AR - USA

Vette(s):
69 Conv #'s Match 427, TKO-600, 3.36HD-Posi, T/T, PS, PB, PW, SP, Lthr, Comp Mag 270 & Pro Rlr Rockers, Edel Air-Gap RPM, BG SD 750 MS, MSD 6AL+Tach Dist+ Blaster SS+Wires, Hly Bl Fuel Pump, K&N, Jet-Hot Hkr Side-Pipes,Steeroids, Al Rad, Spal Fans

Joined: 4/24/2004
Posts: 3194
[QUOTE=Gunslinger]My '69 has the M21 close ratio...very little spread in gearing at all...even in slow to moderate driving I'm banging gears fast.  Bang, bang, bang and I'm in 4th.  Actually, unless I'm on an upward slope, the car doesn't really need 1st and 2nd gear.  Starting out in 3rd is no trouble at all.[/QUOTE]
 
this is the entire reason I am not installing my M21 in my car.  I am leaving it on the shelf and maybe one day ill get Adam to rebuild it just for thoroughness since the numbers match.
 
the close range is useless for a car that you actually drive..  I found I usually shifted 1,3,4 or just 2,4
 
 


____________________________________
http://www.vetteprojects.com/bmv
 Reply Reply  Quote Reply w/Quote
8/24/10 10:45am - Reply: 'M20,21,or 22'
VetteSpecialties
Former Member
- Send Private Message


Mounds View, MN - USA

Vette(s):
70 LT1 coupe, 69 350 HP coupe, 69 390HP 427 coupe, 71 LS5 convert, 85 coupe, 93 coupe

Joined: 5/24/2007
Posts: 1031
The tank sticker on my '70 has a column(the second from the left), with the option number.  In my case it says 03M21AA, for the M21 close ratio.  I believe '72s used the same format.

Larry


____________________________________
Corvette Specialties is your best source for Corvette parts, accessories and gifts. www.CorvetteSpecialties.com

   





 Reply Reply  Quote Reply w/Quote
8/24/10 10:46am - Reply: 'M20,21,or 22'
dskopp
Former Member
- Send Private Message


Oak Creek, WI - USA

Vette(s):
1981 Great White Shark. Red Interior, 350/190hp. PS, PB (SS), A/C CC, T-Tops, Going to remain as Stock as possible. Served three years in Active Duty Army, then Retired Air Force after 34 years! Badger State Vetts Car Club. 175,000 Original miles!!

Joined: 5/21/2008
Posts: 1956
BINGO !! (I just had to say that!).
DanRolling On The Floor Laughing


____________________________________
          



(click to see a larger image)
 Reply Reply  Quote Reply w/Quote
8/24/10 11:47am - Reply: 'M20,21,or 22'
Adams' Apple Lifetime Member
Lifetime Member
Moderator
- Send Private Message


Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19459
The close/wide ratios have more to do with the spread between 3rd and 4th than anything else. On the wide ratios, shifting from 3rd to 4th is an incredible drop in rpm, compared to the close ratio.
The close ratio idea was to use a low rear gear(for bottom end help), and keep the engine in it's powerband during the shifts to the next gear up, OR down.
The wide ratios are much better suited to normal, "daily" driving, imho.


____________________________________
Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
 Reply Reply  Quote Reply w/Quote
8/24/10 7:16pm - Reply: 'M20,21,or 22'
manchestershark Lifetime Member
Lifetime Member
- Send Private Message


Equinunk, PA - USA

Vette(s):
1972 conv, 4-speed, 350, 200hp, numbers match, rally wheels, war bonnett yellow w/white top. good condition, nice driver.

Joined: 10/31/2007
Posts: 1901
I have nothing in the space after transmission.  Only the word base.  Guess I have a M20-wide ratio.  Thats good as far as I am concerned. I am looking for mileage for the most part, not smoking tires.  THANKS to all!   Mark

____________________________________

Click on image for full view
 Reply Reply  Quote Reply w/Quote
8/25/10 12:03am - Reply: 'M20,21,or 22'
cthulhu Lifetime Member
Lifetime Member
- Send Private Message


Hot Springs, AR - USA

Vette(s):
69 Conv #'s Match 427, TKO-600, 3.36HD-Posi, T/T, PS, PB, PW, SP, Lthr, Comp Mag 270 & Pro Rlr Rockers, Edel Air-Gap RPM, BG SD 750 MS, MSD 6AL+Tach Dist+ Blaster SS+Wires, Hly Bl Fuel Pump, K&N, Jet-Hot Hkr Side-Pipes,Steeroids, Al Rad, Spal Fans

Joined: 4/24/2004
Posts: 3194
in reality mileage wont matter which one unless its all stop and go.  the top gear is 1:1 in all 3.

____________________________________
http://www.vetteprojects.com/bmv
 Reply Reply  Quote Reply w/Quote
8/25/10 6:56am - Reply: 'M20,21,or 22'
manchestershark Lifetime Member
Lifetime Member
- Send Private Message


Equinunk, PA - USA

Vette(s):
1972 conv, 4-speed, 350, 200hp, numbers match, rally wheels, war bonnett yellow w/white top. good condition, nice driver.

Joined: 10/31/2007
Posts: 1901
 WOW! that is a statistic I was not aware of. THANKS  Good to have that info stored away.

____________________________________

Click on image for full view
 Reply Reply  Quote Reply w/Quote
9/9/11 4:14am - Reply: 'Re: M20,21,or 22'
yostusota
Former Member
- Send Private Message


York, PA - USA

Vette(s):
1969 daytona conv. all original 350 350 380 4 sp w/air..and hard top

Joined: 5/18/2010
Posts: 1518
Mark you can also tell if its a close ratio if it has 3 lines going across the splines of the input shaft..of course this only matters if you are looking for parts because driving a close ratio versus the wide is very different..I rarely use second gear..just don't need it..unless I am winding it out... being 4th gear is the same on both I like the close ratio..I can hit 60 in first gear!! Rich

____________________________________

My first parade at Carlisle 2010
 Reply Reply  Quote Reply w/Quote
9/9/11 8:34am - Reply: 'Re: M20,21,or 22'
Jaws79 Lifetime Member
Lifetime Member
- Send Private Message


Sykesville, MD - USA

Vette(s):
1979 Corvette Coupe Corvette Light Blue Midnight Blue interior Mirrored Glass T-tops

Joined: 4/27/2008
Posts: 4211
Don't you be doin' no speedin', Rich! The MAN will get you!!!!!!!!!!!!!  LOL
 
Barry
 
Big smile


____________________________________
"Down on the Boardwalk...

(Click image to see a larger version}
 
Lifetime Member #181
 Reply Reply  Quote Reply w/Quote
 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
 Forums -> C3 Driveline Components
(Moderator: Adam Wartell, Norsky, Adams' Apple)
 

 
Official C3 Vette Registry Community:
Home | Forums | Email | Who's Online | Clubs | Events | Member Stats

Other Official C3 Vette Registry Areas:
Members | Research | Shop | My Account | About C3VR
 

Corvette is a registered trademark of the General Motors Corporation(GM) & Chevrolet Motor Division. Vette Registries, LLC is responsible for all site content (except for member submitted content or where otherwise noted) and does not claim or imply that Chevrolet or GM is responsible for Official C3 Vette Registry content. Vette Registries, LLC is independent from GM and is not affiliated with, sponsored or supported by GM.  Copyright/trademark/sales mark infringements are not intended, or implied and are in fact used to support GM, Chevrolet and Corvette

Official C3 Vette Registry content is Copyright 2001-2017, Vette Registries, LLC. Content may not be reused without written consent. All Rights Reserved. NS

Corvette (Vette) Model Years on this site: 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 30