8 3/4 What will it take ?

No way would I use a 8-3/4 at that level especially since your using a 727. Remember that if you break the driveline you'll need to totally disassemble the 727 and inspect and possibly replace the sprague.

For those that keep insisting that the Dana wasn't used or needed when the first Hemi's ran I'd like to reiterate what Myron said about the traction level back then vs. now. Back then car's did not hook up anywhere close to as good as they do now and that makes a huge difference. You can have 2000 hp but if your running F78-14 inch tires you probably wouldn't break a 8-1/4 rearend cause all you'll do is spin the tires.