Dang Yo

i just got a new b16a 1st gen longblock from hmotorsonline and i have to say it is cleaner then my old b16 that was in my car, well my old motor is a 1989 b16 and my new one is a 1991, so my question is, my old motor on the head it says PR3-3 and on my new one it says PR3-2 what are the differences in these heads? also my injectors on the old motor have a white dot on them and on the new one they have a blue dot? whats the differences? thanks for the help in advance