My 99 was running strong at 133k. It went into another 6GA after mine.
haha this! except mine was 170,000 i think and still running strong. Shipped it to a guy on the East Coast with a return warranty (that's how confident I was lol).
I'm afraid I never did anything special to prolong the life of my trans.
Everything in this thread seems like good advice, I'd also like to throw out the auto trans cooler. I've heard mixed reviews on those helping the life of our transmissions.