Re: [Chevelle-List] 4 speed problems

[Don Overpeck]

Larry, I finally pulled the tranny out of my Chevelle. According to the numbers & photo comparisons it is a Muncie. I believe it is a M20. The # on it is P8B12. It has a 10 tooth front spline & 27 tooth rear. It has two rings on the front spline. I think it is a wide ratio M20 but am not certain. I know from the cut of the gear teeth that it is not a M22. Here are all of the numbers that I can find on the trans. Case: 3925660 Tail Housing: 3857584 Vin: P8B12 Side Cover: 3884685 Front Seal Cover: 3915020 Stamped into the case: 18G12259 A metal tag that was attached to the side cover: 3924704   Researching all of the sites that you guys gave me, I believe this is a M20 wide ration that was made in Feb. 68. It is probably the original trans. If anyone can decipher the numbers & tell me for certain that it is a M20 I'd appreciate it. I found a couple of places that will sell me a rebuilt M20 for about $700. I don't know if that's a good price or not but they seem to be hard to find. Thanks for all of your help, You guys are great & this list is great. I've learned a lot from it. I hope I can help some of you guys someday. Don Date: Saturday, June 30, 2001 12:45 PM Subject: Re: [Chevelle-List] 4 speed problems if it is a Muncie it will read lie this: P  8  E  03 P: prefix=4 speed passenger car except Corvair the Saginaw wide ratio (low performance) and regular wide ratio will have the numbers: maincase = 3925656 extension housing = 3860042 side cover 3920798 the Muncie m20 wide ratio, m21 close ratio and the close ratio m22 will have the numbers: maincase = 3925660 extension housing = 3857584 side cover = 3884685 find out which transmission you have and the we can then figure out if its a close or wide ratio.                                                             Larry