sututututu

What's up everyone I'm about to start building my gs. I bought the car off a kid my age for 100$ and a PS3. The car wouldn't start unless jumped and and would die when going into drive. All it needed was an alternator and the battery wires cleaned. I've been driving the car for a couple weeks and the motor sounds really good so I think I'm ready to start tearing things abart.

I'm going to start with the transmission since I'm having problems with it.
anyone have any experience with these rebuild kits

http://www.importperformancetrans.com/catalog/toyota-lexus-transmission-rebuild-kit/a140-toyota-performance-transmission-rebuild-kit-1790.html

I was going to do a manual swap but I think I'm going to keep the auto tranny. How much can these transmissions handle stock?