the b16b is th most efficient out all b series motors.
for example , the itr has b16 head , which everyone knows
but the valves, cams, springs, and retainers are b18 for the block
and has a slight port and polsh. And as for the b16b both parts of the head have port and polish , and the cams work harder , at the mid and top end in high rpms.....so yes it is currently the b16b
is the best b-series made out of factory......