Re: [Chevelle-List] 4 speed problems

[Don Overpeck]

Larry, Thanks, it does. I know mine has two grooves. I'll go count the teeth to be sure. Thanks again, Don -----Original Message----- From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] <[EMAIL PROTECTED]> Date: Tuesday, July 10, 2001 3:35 AM Subject: Re: [Chevelle-List] 4 speed problems don: m20 gear ratios are as follows 1st: 2.52:1 2nd : 1.88:1 3rd :1.46:1 4th: direct reverse:2.59:1 Both the m20 and m21 carry the same casting numbers. The 1966-70 m20 (wide ratio) has 10 teeth on the input splines and 2 grooves. The 1966-70 m21 (close ratio) has 10 teeth on the input spline and 1 groove. the 1966-70 m20 and m21 both have 27 teeth on the out put spline 1966-70 m20 and m21 countershaft pin diameter is 1 inch there are 21 maindrive teeth on a 1966-70 m20 there are 26 maindrive teeth on a 1966-70 m21 there are 25 teeth on a 1966-70 m20 cluster gear there are 27 teeth on a 1966-70 m21 cluster gear So as we can see the output splines have different amount of grooves, different amount of teeth on the maindrive and different amount of teeth on the cluster gear. I hope this will help you out.                                           Larry