8 3/4 tough enough?

Yeah at 425hp im leaning to set up issues aren't right.

The ones we have pushing the spanner are in the 800 area and leaving in the 6000 rpm area off a TB, round after round SS classes
If you're not doing that im not worried about the use of a 8.75.

However for a drag only car making more than 650 at real world weights the simple fix is the AL case, for the car needing the factory case for rules or street use the fix is a little more involved to stop the problem.