Originally Posted by sxecrow
It will never rev as high as the c5, though, correct?
Not correct.
You can rev an ls 89mm stroke to the limits of your powerband i.e. 8900 rpms etc. You simply need the proper rod bolts on ls rods to do so.
If you decide to run oem pistons again, you will also have to remove 1mm of space from each side of the piston to run ls rods.
IMO, 89mm stroke is going to be fine for you.