Changing from 7 1/4" to 8 3/4" rear end questions

, not on a 67-69. It would be solid
67 - 7 1/4 = 2 piece shaft. The outer tube (red arrow) is attached to the inner tube (green arrow) by rubber.

PXL_20211026_035225251~3.jpg

67 - 8 3/4 = 1 piece with tapers on each end like photo shown above.

I don't mean a 2 piece shaft like this

Screenshot_20211025-214137.png