'72 Valiant Prepare for Power!?

All great answers guys! What do you guys think...should I get these things installed before or after I get the new engine put in? I have a guy ready and willing any time I am, he isn't busy for the next 30 days so I have a little bit of a crunch. Heck, he might be able to install the roll bar, subframe connectors and torque boxes too, I need to make some calls.

What would you guys say the max HP and TQ with the roll bar, torque boxes and sub-frame connectors installed on a car are (just as a future reference)?