I believe all the F23 motors are the same. The only differences are if it's VTEC equipped and/or the Emmission specifications. For example

F23A1....SOHC VTEC (150hp)
F23A4....SOHC VTEC (ULEV-148hp)
F23A5....SOHC NON VTEC (SULEV-135hp)

The F23A4 motors are sold in Ca, and parts of the North East . It's only down 2hp, but nothing an Intake won't fix.

Check out these links for more info
Link 1
Link 2