AFAIK, If it came off a 258 it should work. T150, and I think, T176 bellhousings are already drilled with the same pattern as the T18. T4 and T5 bellhousings should work, but need to be drilled for the pattern.
On my 258/T4 to T18 bellhousing the bottom two holes were easily drilled and tapped as there were indentions there locating their position. For the upper two holes I just bolted the bellhousing on with the newly made lower holes, marked them, removed the bellhousing, and drilled and tapped.
The pic is of how mine turned out. You can still see some of my marks if you look close.