streetcar540

need someone to tell me where is the best place to find a complete Lq4 6.0L takeout with a 4l60e trany. even just the motor would be ok. I guess i could find an already built trany that will handle 550hp.
I want to install the L92/L76 head/intake combo with the comp cam from the car craft article. and put it in a 68 camaro. need help please.thanks