i am willing to bet that the ecu will make a diff. in fact i would put money on about 10-15 hp and 3-5 ft/lbs of torque. the h23a was for a wagon that was usually awd and auto i believe, plus it is OBD2. i KNOW that converting to OBD1 on an h22a is worth 5-6 hp as it is.
weight wise it would weigh within 15-20 lbs at most.