Notice how the only difference between scenario 1 and 2 is the engine stamp, and the additional oil line for the B18B. Other than that, the two setups are structurally NEARLY the same. Same bore, same stroke (same rods and crank), same deck height, yadda yadda yadda.

In the arena of the B18 motor, why go with a B18A/B block when you can get a B18C block for less than $500? To do a LS/VTEC properly, you have to yank and disassemble the motor ANYWAY. Why not just have a B18C ready to go and avoid any chances for problems?

The B20B/Z CRV block is exactly the same as the B18A/B block except for the 84mm bore size of the B20 motor. They both have the 89mm crank. So I can understand turning that motor into a VTEC if you don't have the funds to sleeve a B18C block. But a CRVTEC WILL NOT pass smog in California.