A little bench-racing/help with plans

[Ratpick]

Ok, I know some you guys love this- "you should do..." But really I would like to hear a little advice before I get too far into my truck. It's a 67 C10 longbed. Im going after the hot rod/70s style lowrider I've always wanted. I'm about to dig in and start some work, so far what I have parts for is: front disc, 12bolt with 3.73 and posi(5lug), rear air bags and power steering. Also have a 700r4 and the 350 will get a mild carb/cam/intake/headers upgrade.
So here's some of my questions- what about trying to move engine mounting back to other holes? I'm going after a truck that will handle so any weight transfer will help, but is it worth it or too much trouble? I'm also planning on some mild frame bracing- some boxing and X-ing. I've been scouring previous threads about that. I want it stiff so some new sway bars will work even better. I would love to swap a T56 but that will have to wait til I have more money someday. Though I am planning a rack-n-pinion instead of the slop box and flop arm setup it uses now.
Ok shoot...