Pinion yoke fit

Hi All

I am building a new 489 center section to replace the 741 unit unit that is in my car today. The 489 case I have was empty when I received it. I have rebuilt other differentials (mainly heavy equipment rather than automotive) but never an 8 3/4. Without the luxury of taking one apart, I have a question regarding how tight the pinion yoke should fit on the pinion.

I am test fitting all my parts before final cleanup and assembly and noticed that the pinion yoke fits tight and seems to have a slight taper. I believe this is correct as this taper is what seals oil from leaking around the splines. If this is not the case please let me know.

Also have a question regarding the correct dimensions for the carrier cap bolts. Mine have a little corrosion on them. I haven't found a source for replacement hardware.