engine question d15/d16

would keeping my d15 block and swapping the head with a d16 head and change the ecu to a p28, and hook up the vtec wouldnt it give me about the same power, and it would save alot of money as just swapping the whole thing cause wouldnt still be like the same thing or at least would it put me over a 100 horsepower.

D15, hmm. There are like 3 different ones. Depending on compression you might get up to what the d16 is putting out.
100hp would be expected at the wheels.
If you have a CX/VX or a california car: they all have a cat in front of the engine, i would suggest that header would be put in. Also replacing CX/VXs Throttle body and intake manifold would be recomended. Those are ridiciusly small. THe Dx tb is the same as SI/EX. I know also that B-series tbs will fit, so you might look into those if you want.
hope this helped