The ITR block has a number of advantages over a GSR block, but none of them are going to matter if you're swapping out rods and pistons.

The ITR crank is a good deal better than the GSR's, but it really isn't going to make a difference if you have everything properly balanced when you put it back together.



It's also very obvious you don't know anything about building up a B series motor for boost, or boosting in general. I'd just hang out and learn some info before you jump into this. Otherwise you could end up with a $5,000 paperweight.