Hi, I've just changed my cylinder head, intake, rocker arm and push rod put now I need to put some money on my transmission and differantiel...

So my first question is: Can I just rebuild my 700r4 with a kit like this if I need to handle 500hp?
http://www.summitracing.com/parts/TCI-378900/

Secondly, I have a stock differantial not ratchet and not locked...
what I need if I want to have ratchet one does I just need this?

http://www.summitracing.com/parts/PWT-2210-LR/

And finally I need help to chose a good torque converter does this one is good for me?

http://www.summitracing.com/parts/HUP-21-20L/

Thanks for your time!

 

Trying to do any rebuild yourself is gonna be a nightmare unless you're taking a relevant class in a trade school, or have a friend who really knows transmissions. There are special tools required, and these kits don't include any upgrade parts beyond clutches, steels, bands and shift kits.
Before thinking about a differential, you need to consider what gear ration your 500 HP engine wants, and you didn't specify what heads or cam or anything. The stock axles are marginal behind 500 real HP, even with all of the available upgrades. and you can't choose a torque converter without knowing the cam specs and the axle ratio. Everything has to work together. Makes me worry how you matched your cam to your heads.