When talking about lockup converter failures - a lockup and non-lockup converter are almost identical inside except the lockup piston, seal and friction material. Any 727 or overdrive 46 trans with the 10-3/4" converter built before 2002 has the potential to fail if used behind high torque high load applications. Think 360 van or truck hauling a enclosed trailer while lockup - worse if in 4th/OD. We made a change to the lockup piston around 2002-2003 that eliminated this condition. The other condition is high throttle low speed use in any gear when the lockup is not applied - you will likely balloon the converter enough to fail the unit. Most guys never check for this. The heavy duty converters have thicker front covers that help prevent the front cover from deflecting - and if you add an anti-ballon plate to the impeller - then you are in good shape. And don't compare FWD to RWD lockup failures - two different animals. When Chrysler launched lockup - the lockup disc was a floating disc design - that in itself caused failures.
We have been bonding discs for over 20 years now.