Blower Boost

I just restripped 2 SSI top fuel style superchargers for a customer of ours that were purchased from the Hartmans.My customer asked me what kind of boost they should make.I cant answer his question because all we ever had were hh roots blowers.If he were to overdrive @ 50% do any of you guys know what an approximate number would be.Thanks in advance

 

Go to this site, sigh up, fill out all the pertinent information, and it will tell you, very close.
http://www.fuelinjectionenterprises.com/members/blown.htm