What OD trans to hold 700 ft lbs?

I am putting a 518 behind a 440 with a single turbo. They are holding up behind those torque monster cummins . They also offer upgrades, such as hardened input shafts and beefier planetarys.

In this pic the planetarys (on top)
are the upgrades to the stock ones below. The upgraded ones are from the heavy duty 48re tranny and were not expensive.