Most of you have it right. There's been FOUR 3.1L OHV GM's in my surrounding family over the past 14 years. So I think I have some experience to compare to my 99 SVT.
The 1989/1990 calibration was such that the throttle response all happened early in the gas pedal's movement. First gear was pretty short. The diameter of the wheels back then was small too, making the effective gearing that much shorter.
So the first 25-30mph comes up quick, and then you're starting to choke. Great for peeling out though.
Top speed 1989 Regal (heavier than Beretta): a non limited 118mph.
Brian Dors
99 SVT
95 Cutlass Supreme 3.1L
