I recently bought a 1991 Civic LX 5-speed. It has a D15B2 block with what appears to be a D16Y7 head. However, it has the DPFI intake manifold etc. How difficult and expensive would it be to upgrade to a MPFI OBD2 that this head supposedly had originally? What would be the results of rebuilding the bottom end, which is a D15B2, up to 11:1 compression with the D16Y7 head and MPFI OBD2? Please assume that I have no interest in swapping to a B16 engine. I just want to make this engine as realiable and efficient as possible with a little above stock hp.