I'm swapping a lower mileage d15b2 motor and head into my 92 Civic d15b7's chassis. Should I keep the b2's cam with the motor or swap over the b7's? What will be the effect if I leave in the b2's? And why would it have that effect?

Just the motor and head are being swapped. The intake, exhaust, dist, coolant housing and tranny are staying with 92 chassis.