Both the CRX and the Del Sol came in different trim levels. Both had trim levels with 13" tires (CRX HF and Del Sol S) and 14" (CRX Si and Del Sol Si). Rather than having different VSS sending units or gauge clusters, they prolly used the same ones. So since the 14" trim levels had the larger tire diameters, the ODO/Speedo was calibrated to those and that made the 13" trim levels over register. This is just my hypothisis. I have no proof whatsoever to verify such hypothisis. Yes, I am willing to admit that I am guessing here.
I'm guessing that the 14 inches tires + wheels were roughly the same diameter as the 13 inch tires + wheels. For the 13 incher they probably used 175s, and on the 14 incher they might have used 160s or 165s. I'm sure that was the easy solution to the problem.
I've got some work tomorrow so I should have sufficient dinero to buy a d16y8 head gasket from honda and an IM gasket from who cares where. This means that I will be doing the head swap with the b8 head sometime next week (hopefully squeezing it in to 2-3 hours and not having anything blow up).
What this means for those not in the know is that my engine will become functionally equivalent to an entire d15b8. Of course the block is different but those differences don't mean to much as it is the head casting, valve configuration, and cam that defines most of how the engine functions.
CRX Stats For Loving (I've used the CRX HF as a Parallel of the Civic CX, even though the engines are ever so slightly different, first is HF and second is DX):