You can bore the stock liners .040" over. I like to bore them .010" over. The displacement increase in either case is virtually insignificant but the .010" number results in a stronger liner and it's an easy number to work with.
I have 8.8:1 non interference forged Venolias. I can have them made as 8.0:1 as well.
Greg Gordon,
www.hiperformancestore.com