489 Differential ??

[cuda-cable]

I've got a 73 Cuda....489 case diff, just got new sure grip and gears in it. FYI thou when they pulled it apart the pinion shaft is a 29 spline vs a 10 as apparently most are. Had to get another gear set to fit it and was available from Strange Eng'g in case someone else has the same problem. Folks at Richmond Gear only have the 10 spline parts.

Any advantage one to the other ,other than parts availability now 34 yrs later?

[tactransman]

Yup,the later differentials are 29 spline,they don't tell you to watch that when you order your gears,do they.

[matt63]

When you order gear sets I though you had to specify 741,742 or 489 due to different pinion shafts?  They are all different.

[HP2]

They all have different size pinion shafts, but they also have coarse and fine spline choices. Just like four speeds.

[Chryco Psycho]

both style yolks are available in small or large U joint & usually if you have one the new gear set will be the other spline