1989 honda civic head swap?

We changed the 1.5 head to a 1.6 non vtec head. Car is non vtec originally. Now the.car wong rev past 4 thousand rpms. We used the stock 1.5 distributer. Can that be our issue. And should we have swapped the obd0 computer to obd1? Any help would be much appreciated.

Let me see if I understood: Both non VTEC heads. You're putting a 1.6 head on a 1.5 block? Which head gasket did you use? Or you're putting a 1.5 head on a 1.6 block? Again: Which head gasket did you use?
The problem is timing. This link may help:
http://www.hondahookup.com/forums/showthread.php?110095-will-a-1-5-cpu-run-a-1-6-%28non-vetc-head%29

You failed to mention exactly what motor both are. D15 what? D16 what? Are you mpfi or carborated? What ecu are you using? Its not your timing thats off. My little 1.5 was off a tooth and still reved over 6k rpms.