Interesting spec info here
. 3800 has a very mild (less than 300 degree) cam with a very broad and flat curve (how you can have 200 lb-ft at 2000 rpm and still 167 lb-ft at 5200 (84% of peak), a 3200 rpm torque band is very wide.
This makes sense since for maximum efficiency you want the torque peak at the maximum cruise speed and most Bonnevilles are barely turning over 2000 rpm at 70 mph in o/d lock-up.
Cars of the 60'* and 70'* had axles considerably longer, I had a '72 LeMans wagon with 400 cid and "economy" (3.0
axle and it was turning 3200 rpm at 70. This was a big part of the 15 mpg max. Correspondingly, the torque peaked somewhere between 3000 and 4500 rpm depending on the state of tune.
This meant when you jumped on it from a stop light, the torque converter jumped to the 2200 rpm stall speed and then began to wind with the torque constantly increasing until you hit the peak. This gave you that "feeling of accelleration" which was really feeling the *change* in acceleration.
OTOH the "C" engine jumps immediately to max torque (what gives you acceleration) and just holds it near there until time to shift (which is in the 4000s). That constant acceleration means it does not feel like it is going faster, it just does. This is why many people are surprised when they look down and see how far the speedo has wound around.
BTW "real world" 0-60 for a good running Bonne with a "C" engine is around eight and a half seconds which is really pretty quick, it just does not seem like it.