need numbers help please
Thread Starter
Racer
Joined: Apr 2002
Posts: 461
Likes: 0
From: Columbia Tennessee
need numbers help please
Can someone tell me if this 4 speed transmission is a close ratio?
It's from my 1967 coupe, small block...
Cover number 305264
Casting nuumber 3925661
Tail casting number 3978764
26 spline
11 inch clutch diameter
Thanks.
It's from my 1967 coupe, small block...
Cover number 305264
Casting nuumber 3925661
Tail casting number 3978764
26 spline
11 inch clutch diameter
Thanks.
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
That's a '71-'74 Muncie. The Muncie "P"-code is stamped on the passenger side of the main case, on the vertical rib just forward of the joint with the mid-plate; it will have either an "A" (M20), "B" (M21), or "C" (M22) as the last digit. Assuming nobody has changed out the guts, that digit will tell you what it is. 
Safety Car
Joined: Aug 2000
Posts: 4,148
Likes: 642
From: Bandera Texas
The main case and tail shaft first appeared in 1970. The cover should be 3952647. Check for a P code for Muncie. It may have a vin number from a vehicle, as these were used in Chevelle, Camaro and passanger applications as well.
All had drain plugs. A letter "A" was added to the plant build date code to signify 'wide ratio'.
Wide rato trans has fine spline, 21 tooth input shaft.
26 tooth shaft was fine spline and used from 71 thru 74 in close ratio transmissions.
All had drain plugs. A letter "A" was added to the plant build date code to signify 'wide ratio'.
Wide rato trans has fine spline, 21 tooth input shaft.
26 tooth shaft was fine spline and used from 71 thru 74 in close ratio transmissions.
Race Director
Joined: Oct 2005
Posts: 12,470
Likes: 1,548
From: Camp Verde AZ
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist
Originally Posted by JohnZ
That's a '71-'74 Muncie. The Muncie "P"-code is stamped on the passenger side of the main case, on the vertical rib just forward of the joint with the mid-plate; it will have either an "A" (M20), "B" (M21), or "C" (M22) as the last digit. Assuming nobody has changed out the guts, that digit will tell you what it is.
Either you have a really good memory, or you have a book of some sort that has all this info.
I don't suppose you would mind sharing the name and source of this book(s) that has all this ID/casting number info?
It would make boneyard and swap meet trips much more fun to know exactly what I am looking at.
Thanks,
Doug
Thread Starter
Racer
Joined: Apr 2002
Posts: 461
Likes: 0
From: Columbia Tennessee
So am I to assume that since there are 29 splines, this is a early 70's close ratio tranmission? I'll check again, but believe there's an A on the side vertical number which should mean M20 and if that's the case, this is a wide ratio?
Thanks
Thanks
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
Originally Posted by AZDoug
Hi, John,
Either you have a really good memory, or you have a book of some sort that has all this info.
Either you have a really good memory, or you have a book of some sort that has all this info.
This year at Carlisle I was working on my car on the field when John dropped by to say hi. He saw me fighting with a part and told me to forget that POS aftermarket part from NAPA and whipped off the proper part number I needed.
I went over to the paragon booth, bought the part number he told me, and no more fighting with it - the job was done 10 minutes later.
I wouldn't be surprised if at least half the time or more when he starts mentioning part numbers on here he just knows them without looking them up.
Scary, isn't it?!
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
Originally Posted by gilmore1967
So am I to assume that since there are 29 splines, this is a early 70's close ratio tranmission? I'll check again, but believe there's an A on the side vertical number which should mean M20 and if that's the case, this is a wide ratio?
Thanks
Thanks
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Melting Slicks
Joined: Jul 2004
Posts: 2,867
Likes: 195
From: Maryland
Originally Posted by AZDoug
Hi, John,
Either you have a really good memory, or you have a book of some sort that has all this info.
I don't suppose you would mind sharing the name and source of this book(s) that has all this ID/casting number info?
It would make boneyard and swap meet trips much more fun to know exactly what I am looking at.
Thanks,
Doug
Either you have a really good memory, or you have a book of some sort that has all this info.
I don't suppose you would mind sharing the name and source of this book(s) that has all this ID/casting number info?
It would make boneyard and swap meet trips much more fun to know exactly what I am looking at.
Thanks,
Doug
Safety Car
Joined: Feb 2003
Posts: 4,068
Likes: 27
From: St. Joseph Mo
The Muncie has a propensity to spin the drive gear (input shaft) bearing in the housing. Case may be a replacemnt from such an event. (I have seen more than one sleeved.)
Best bet is to remove side cover and do the math.
Best bet is to remove side cover and do the math.
