hmmm
well the manifold is about as bad flow wise as they come.... i had to register to see the pic, so i copied it to my photobucket and posted it here... please do the same next time..
am i wrong in assuming the price is 2500?? that was what i got from the thread..

there is no doubt it will work, and you will get boost, the question is how well it works... depending on your budget this could be a decent or a really bad choice, stock compression of a non stage 1 engine in 1971 is 8.5:1 so that leaves plenty of room for boost..
looking at the picture it seels like he in mating the square tubing directly to the head, and running long bolts.. i think you can be more than sure you will have a permanent and substantial exhaust leak between the "manifold" and the head the first time you get into boost and it heats up.... also, the long tubes feeding the wastegates could become a "tuned element" at higher RPM generating vibrations sure to crack the welds of not the tubes..
if you make sure you dont run into detonation you should be fine up to atleast500 Hp. your q-jet can be modded for boost (early t-types were carb) it would just require different jetting, and at low boost (below 10 psi) with a blow thru carb you dont really need intercooling as the heat generated isnt that enormous, and the fuel cools in it self...
the cam should be fine for a lo-buck build..
i would personally not run this setup.. id either do a set of logs my self (from round heavy wall tubing), or have a set made that would flow better than the abomination above.. id run external wastegates.. forged pistons.. and get and i would call schwartz and get a set of turbos that are matched to the particular setup...
below is how i like fabricated logs to look... heavy wall.. nice radii.. short tube to wastegate. you could fab up a set your self to fit your 455, or have schwartz do it for ya (if he still does that kind??)