'72 Valiant Prepare for Power!?

Just got back from my machine shop today after a dyno pull on my 408" Stroker...570HP and 475ft/lbs. of Torque! They said I might have to de-tune to make it work in my car. I don't want to de-tune at all, who would?! This is going in a '72 Valiant 4 Door that had a slant six (engine is toast), so, lot's of things need to be done of course. I just never thought my engine configuration would make so much power!
"I have never even seen a Chevy hit that" is what the dyno operator said, haha! He should have got a Mopar!
I have a 3.55 Sure Grip in an 8 3/4 going in, brand new 727 with torque converter stall ~2500, Poly-Loc Schumacher Mounts. I will need a driveshaft of course, should I look for anything special? Planned on 245/60/15 in the back, 205/65/15 in the front (that would make the car look parallel to the ground right?) but will that be adequate?
My main question is, what am I going to need so that my car can handle the power and I will be safe? I thought subframe connectors, but will that be enough? I don't want my car to turn into a pretzel when I lay on it. I like having a full interior, so, if I can steer away from a roll cage than I will. Please guys, I need advice from the pros and that's you.
Thanks,
Cory