That's kind of a loaded question. Are you talking about the amount of horsepower/torque it's capable of taking (used behind a hemi from the factory), age of it, drag racing requirements or? On the Challenger I once owned, I had it replaced when I had the transmission taken out to be resealed. The car only had 32000 original miles on it when I bought it, but the car had been sitting in a garage for over 20 years, and the transmission leaked from everywhere. The only reason I replaced the flex plate was my concern about possible metal fatigue from old age ( Yeah I know, a bit paranoid), but once the transmission was I thought why not. In my mind at the time cheap insurance.
