Going rate?
All of the sure grips interchange between all 3 3rd members. What does not enter change are the gears and the bearings. A489 case requires a crush sleeve in the pinion. This is a one time use part. I believe the 741 and 2 case Use shims to get the same result. For all out Drag Racing A489 case is fine It's not really necessary on a streetcar. Most if not all A bodies came with a 741 case Including big block cars.