well yeah, short gearing makes high speeds for sustained periods pretty bad. My GS-R at 80 mph is already spinning 4,000 rpm. 120 would be 6,000 rpm, and LOUD as hell *eek*
Of course the DB chassis is slower, that's the GS-R sedan!

2g GS-R's were also a DB chassis, oddly enough. My GS-R 3-door is a DC2 chassis. Best time I ever had in the 1/4 mile was 15.01 seconds pretty much all stock, back when it had much fewer miles on the car and trans! It's been MANY years since the car has ever drag raced.