Please tell me what the first part/parts are that break in a high boosted 2005 stock 18,000 mile 5mt wrx tranny. I'm trying to figure out what I should replace and in what order with 350-400 hp. Any info. would be greatly appreciated. Thanks for your time.
p.s. I Did search and found what breaks but just need to know any idea of the order most common. Thanks again!

1. Gears/clutch
2. rear end
3. rear axles

Your mileage may vary though and that advice is based on what I've seen here overall.

good to know