B16A2 should be 160hp, and the SiR2 will be anywhere from 160-170hp.
The Y21 might have an LSD. Jack up the front end of the car and spin one of the wheels forward with your hands while the car is in neutral (and off)- if the other wheel spins forward, you have an LSD, if it spins backward, you have an open diff. If the transmission isn't in the car yet, look through the differential- if it's completely clear all the through, you have an LSD- if there's a bar going through the hole, you have an open diff.