At 400+hp, What kills A904s?

My new engine puts out 450+hp/520+lb-ft at the crank. I’m planning on proceeding with the A904 but I understand this is close to the generally accepted safe range for this unit.

What is the typical failure mode for these transmissions? When do they typically suffer their failures? I always assumed that the moment the tires grab after a burnout was the killer but I don’t know that for sure.

Back before I installed my last engine swap (300hp small block) I had the local shop rebuild it with upgraded bands and clutches, higher RPM governor weight, shift kit. Maybe some other stuff? I can’t remember. It was a while back. I also installed a deeper pan. I’ve been running the cooling lines through the (upgraded) radiator but I may add an external cooler for some extra insurance. I’m pretty sure I also bought an upgraded sprag but I can’t find my receipt for that part so I’m not positive.

Not sure if this makes as difference but im running a mild 2800rpm converter, 4.10 axle. I don’t plan on running drag slicks but I will be on 200 TW summer compound tires this year.

I guess I’d like to know how to be kind to this thing and minimize the conditions that kill them until I’ve saved up enough cash for the manual swap. :)

Thanks!