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raycow · 08-05-2010, 10:18 PM

You have a 10 spline input and 27 spline output. A Saginaw 4 speed would be a direct replacment, but if your Sag 3 speed didn't die from natural causes, you will very likely grenade the Sag 4 speed too.

This means you want something stronger, like a Muncie or T-10. If you don't want to replace your clutch disc or driveshaft yoke, I think that pretty much limits you to a Muncie from about 63-70. Later ones than that were 26 spline input and 32 spline output.

As for the T-10 and ST-10, I think that spline combination might be kind of scarce. The early ones (up to 63) were 10/16 and the later ones (after 74) were 26/32. These are GM original equipment units. I think the 10/27 combination might have been used for aftermarket, but I'm not real certain about the non-OEM stuff.

Ray

08-05-2010, 10:18 PM	#3
raycow Registered User Join Date: Mar 2003 Location: San Francisco, CA USA Posts: 2,454	Re: 3 Speed Bolt out Swap for M20 You have a 10 spline input and 27 spline output. A Saginaw 4 speed would be a direct replacment, but if your Sag 3 speed didn't die from natural causes, you will very likely grenade the Sag 4 speed too. This means you want something stronger, like a Muncie or T-10. If you don't want to replace your clutch disc or driveshaft yoke, I think that pretty much limits you to a Muncie from about 63-70. Later ones than that were 26 spline input and 32 spline output. As for the T-10 and ST-10, I think that spline combination might be kind of scarce. The early ones (up to 63) were 10/16 and the later ones (after 74) were 26/32. These are GM original equipment units. I think the 10/27 combination might have been used for aftermarket, but I'm not real certain about the non-OEM stuff. Ray