confusion... 3S-GE vvt-i, dual vvt-i? single vvt-i? Options

[kanazai2001]

hi~ i'm a newbie here... and i'm having a ST model... im apologized 1st if my c2PiGz Q annoying anyone here...

i would like to swap my stock engine with 3S, but i'm kind of confuse regarding the 3S-GE vvt-i thing... i got the bottom info from a japan website:

"DUAL VVT-i which also the control of the exhaust valve is done tempering 4 cylinder sport twin cams which were lifted, in addition to the BEAMS (Breakthrough Engine with A Mechanism System) 3S-GE DUAL VVT-i former inhalation valve, (Variable Valve Timing-intelligent) it loads. According to engine rpm and accelerator opening, because the computer optimizes the opening and closing timing of the inhalation and exhalation of air valve continually, inhalation and exhalation of air efficiency improves furthermore over entire area, raises output torque. "

it is the red top 3S-GE vvt-i a DUAL vvt-i?

furthermore i would like to convert my ST to GT4... is GT4 a FULL TIME 4WD or manually selectable or auto engage during wheels slide?

thankz...