well im fixing to send my blackbird back to. gmmg for a phase 2 package and. was not for sure if the stock T56 tranny. will handal 450rwhp and if it cant what tranny. to go with

 

You will be fine. T56s are pretty strong units. There are some things you can do to make them stronger, but stock they aren't to shabby.

 

You'll be fine. My buddies got the Phase II on his and no problems that I know of. He did upgrade to a Spec Stage 4 Clutch though. Which might've been some overkill, but he's got something else that'll be done tomorrow that'll it'll definately make the clutch worth it .