Thanks, that eases my mind some. The guy I had look at it said that I would have to take the whole center section apart including the sure grip to put these buttons in. Gear in question is a 488 and I want to transfer the sure grip to a 741 3.91 gear case. I'm not familiar with the 8/34 but I'm learning. He said that it would all have to come apart to install the buttons and they had to be peened with a hammer to stay in. Thought he knew what he was talking about ect but so far I haven't been impressed. Yes I will be using the taper bearings so they will need to be in place. One other question. I replaced the pinion seal in the 741 case and there was a small shim as it looks like behind the yoke. I put the shim back in and reinstalled the yoke and it seemed tight. So I checked the other 2 741's I have and neither one had this shim. I removed the yoke 0n the center section that I replaced the pinion seal and removed the shim then reinstalled the yoke. Was a little snug still but not like before? This rear has been dry with no lube for about 5 years and was in a plastic bag to protect it. I lubed up the bearings and no it does turn more freely. I honestly don't know if this washer type shim is supposed to be there behind the yoke or not as the other 2 didn't have this shim. Thanks again for the button answers, really helps to know these small things. So far I have been a little leery on his comments on these center section questions. I figured he would be the one to go to as he is an old Mopar hotrodder.