I took my VX out to the dragstip once last spring... I managed several back-to-back 16.3x runs pure stock except the Injen intake. I've since added the interceptor and PV muffler as well, and would love to know what difference it would make. I'm betting nearly 1 second, based on the SOTP meter.
BTW... just FYI - reaction time does not count in your elapsed time. The clock for ET doesn't start until you move. Oh, and also, .612 is not bad at all -- a "perfect" amatuer light is .500.
Mark