Ive got a stock AU trans with heavy duty cooler and electronic adj. shift kit fitted. Im currently pushing 194rwkw thru it now. I wanna push a little bit more power thru it but think it could be too much for the stock internals.

Can someone tell me what the maximum power to the wheels these things can handle before an upgrade/rebuild is advisable?

why don't you experiment with it. see how much it can take, as long as you have got a spare gearbox that you can put back in when it does screw up

ive heard repeatably that the auto trans can handle 300rwkw's whilst the manual t5 can only handle 250rwkw's

thanks gas man. Im hearing similar reports. Thats good news for me.