The case is the same size.
Take the nose cone off your old trans and put it on the new one. You must first check for clearance between the top bearing on the gearbox and the nose cone. The later nose cone has this clearance cast in.
You also must upgrade your clutch. Remove the center ring from the clutch.
The later trans uses a different TO bearing, so if it didn't come with one, you'll have to buy the late type TO bearing.
