the tall deck CFE chevy and ford blocks are for very large engines, 600+ inches. It is almost mandatory to be able to fit any kind of rod, crank and piston into an engine of that magnitude, along with a raised cam location to clear the crank throws.. Not sure how any type of power adder knows or cares what the deck height of an engines means/matters to it??? The deck thickness is pretty much the same on a 9.5 block as it is on a 9.0 block, if it wasn't, you could deck a 9.5 block down to 8.9 with no issues and still have plenty of deck thickness for boost or a blower or whatever, just depends on which block casting you have and how much you can mill it down as there have been several variations.