are 727 torqueflights okay for drag racing?

[CenTxRacer]

Took an old torqueflight with a manual valve body in it to the local tranny shop to have it looked over. the builder says they are not very good for drag racing, they cannot take much power and the sprags break.
he offered no suggestion for what to use instead though.
Opinions? I was always told a good 727 could handle a lot of horsepower.