I don't see splitting bieng that benefitial. JMO

One of my accounts here has a 67 Firebird with a 455. He is running a TH400 and a gear vendors. On his old combo he was geared 4.56 for motor passes and would use the gear vendor for nitrous passes. Ran 10.0s and he said the shift from the GV is the firmest one the car makes. He has since changed his combo to a roots blower and 3.70 gears I am sure he would or could still use his GV on the track.