Got a question about a 489 suregrip that I just picked up.

So my 68 Barracuda had a 741 case open set of 2.76 gears in it and I just bought a 489 case suregrip with 3.23 gears, what's supposed to be in the car according to the fender tag. So I pulled out my old center section, did some cleaning, and then installed the 489 case. Put my driver's side axle in and tightened it up, then put in my passenger side and then started to try and adjust the end play. I have the adjuster all the way in I think and the axle on the drivers side has a lot of end play on it still. I'm scratching my head. I don't remember looking, but if the button spacer in the middle is missing, is that going to mess up my world and cause this excessive end play?? And if so how would I remedy this situation?? Thanks.


So I was just doing some searching and reading and came across this:

If you have the clutch type and the thrust buttons were missing you would see a tiny hole where the buttons go,

I remember now being able to see a tiny hole in the center where the splines are. Can these thrust buttons be reinstalled?? And where could I buy some if so??
i had to do this on my 66 coronet i had the same issue, i had to pull out break unit down and press the pin in between the 2 buttons. ebay item #330415165417 mopar pinion thrust spacer sure-grip go there and check it out joe