have you seen Leo Santucci's book, he has a small chapter on blowers. They are mainly roots blowers mounted directly on the intake manifold.
Centrifugal blowers should be pretty simple to install because they are placed wherever is more convienient and then plumbing is made to take the air from ths blower to the intake manifold.
there is no reason why you couldn't do this with a roots type blower either, and if you like you can have the air go through an intercooler as well.
Look at how one guy put a roots blower on a ford 300 (scroll down to middle of page):
http://www.inliners.org/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=002007 It looks like an eaton M90 (available in ebay from $150 to $500) in a draw through setup
intersting huh?
Luis