A904 Lock up performance build

I pulled this transmission out of a 5.2 magnum swapped 68 valiant I bought a few years ago. From what I can tell decoding the numbers it came out of a 82 Cordoba(I was told it came from a Cordoba) and the shaft is a lock up type from what I have read.

It works just fine but I am upgrading the car for more strip time than street time and am wanting to know how good of a base for a bracket 904 this transmission is. I want something that will live for multiple years behind a 400-500hp small block. Is this a good starting point or should I get a non lock up 904 and save this for a cruiser?

Please don't mention a 727 I am only interested in a 904 for this car.

Thank you in advance.

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