depending on rpm band a 2.48 may put the car down the track faster because of increased traction ,heres a thought though
;high powered turbo cars with narrower power bands usually go faster with less rear end and trans ratio,and lower powered cars with wider power bands usually go faster with more rear end gear and trans ratio.i run a 2.20 / 1.40 in my 3200 lb 434 chevy malibu with a 4.10 final drive but this is certainly not a turbo buick.we do however make 8 different ratio planets for the th400 to allow close and precise calibration of engine / transmission.