yea man the LS crank is different, 89mm stroke yeilds more CR when fitted with a taller piston dome. the only way to tell if is you clay the motor when you build it if you have enough piston to valve clearance. the valve reliefs on the CTRs are DEEP, they are made for it, also consider the stroke on the B16 is 77.4mm the deckheight on the B18A/B is I believe is the same as the GSR/ITR.
The JDM ITR pistons with the LS crank will give you a good 11.3-11.5:1 at 81.25mm while the CTRs running a higher 12-12.2:1. It all comes down to what you research and do yourself. Thats pretty tall compression my friend, however it may be managable..?! I would invest some time researching the risks running 12:1 on the street.