found out what my truck is rated for got questions now

Ya things have changed since 04 i also have a factory installed trailer brake/tow haul, etc so it would help

One of my family members pulls a fifth wheel (its and old model with one slide) with his 2016 tundra i think he said it had the smaller v8 and it does just fine.

I cant remember if mine is 9k max or 10k i kept hearing different results but with 8400 it should be ok? Since i am below the 2 mentioned

Oh and this truck has nothing aftermarket on it.