727 limitations

There are shops ( Cope and A&A ) making 700hp plus 727's that include special input and output shafts, can easily go $7k plus. If you have a high dollar motor, there's no sense in trying to go low budget on the rest of the drivetrain! Doubt you can use/abuse the trans with that 700 horse when on the street anyway realistically, but you'll need the safety/security of a proper built trans when on the launch pad!