My experience going from a230 to a833od in my 72.

Looking around, the bracket that bolts to the frame SEEMED the same between the 3 and 4 speeds. When looking for a frame mounted bracket, another member measured his from an a833 truck, quick measured the same as an np435 truck in the pick a part. All these measurements were from a 72 (mine) 77(? A833 truck) and a 75(? 435 truck) they may have changed when the body lines changed.

Pivot point on the bell housing. On the side of the bell housing, is a large bolt. There is a separate bracket that bolts to this giant bolt and then to an engine to trans bolt. This bracket sets the angle of the zbar correctly. Without it, your zbar will be lower on the trans side. I'll dig up a pic if I can