blower question on big block
 

what kinda lbs of boost will a 6 71 make on a 468 bbc???

boost depends on many factors, heads, cam, exhaust, how fast you spin the blower, is it stripped....?
what is it you are looking to do...?

Yup, what Ed said. If you want real ballpark figures you can go here:
http://www.blowerdriveservice.com/techcharts.php, but this is just meant as a guideline.