There is really no need for one on each side if you think about it. Inside of the diff/suregrip the is what is known as thrust buttons (clutch type suregrip) and thrust block (auburn suregrip or cone type) the axles come to rest on these buttons or block (sandwiched in between if you will) and the adjuster tightens everything together.
The rearend looks like it has a lot of pinion angle, pointing up..w.whats the correct angle.
Are you looking at it with the suspension hanging or loaded? 4*to 6* nose down. When I did mine I used a straight edge and carried some marks along the tube from the perches before I cut them off and moved them. I just used that same mark to align them to and welded them back on. I ended up with around 6*.
Is there a sure grip in there now? If so the thrust buttons or block should be removed with the green bearings, I would suggest you ask Cass if you talk to him. Although some say they have put them together with them in there. I prefer the Timken roller bearings my self so it's a moot point.