i run the holley projection setup on my XB .
it is a simple bolt up system to repace the square bore carby. it is a throtle body style that uses the standard manifold .
the tuffest job will be fitting a fuel return line back to the tank. everything else is in the kit including electric fuel pump , computer , throttle body, wireing ,etc.
i am real happy with mine for street / highway use and also at the drags etc.
runs smoother , idles better , revs harder , no flat spots , stars easier , and is more economical than any carby i have used.