I also have an Hitachi band saw, model CB13F, with 7 Ampere motor. It does a great job for resawing, as well as normal ripping & cross cutting. I put a 6" riser on it, and a Highland Woodworking resaw blade - the Wood Slicer half inch. This blade does a beautiful job on resawing, the cut sides need very little smoothing to be used in furniture construction. I've never taken this blade off, mainly due to the hassle & my laziness.
I do not remember the widest board I've resawed on this setup, but I know it required the riser block to get beyond the stock 6" maximum. Very happy with the results. I believe the success for this is the blade with the 7 Amp motor, but that's strictly my opinion.