When I bought my '94, I loooked at several Vipers and most of them had the bucking problem. When I found mine, it had absolutlely no bucking at all which was a factor in why I bought this one (more on this later).
After owning it for a few weeks (and driving it extensively with no hint of bucking, ever), I went to my first Viper get-together. The local chapter president (an old friend from my DeLorean days) and I inspected various parts of the car and found that the (I think) passenger side throttle body was only opening ~75% when the pedal was at WOT. We adjusted the cables (per Dodge procedures). As soon as I left the parking lot, the bucking started. The car has bucked ever since.
I've tried adjusting the throttle cables many times with varying success. One of the wizards on this site (maybe not THE wizard) suggested that the root problem may be a stretched throttle cable, which would prevent the system from adjusting properly. The extreme mal-adjustment we found originally was a means of compensating for the stretched cable. I haven't tried the new cables yet as my driving style has adjusted itself to alleviate the problem.
As for the "driver-induced" theory, that can't be the problem in this case. My car will buck violently even when I remove my foot from the gas pedal completely and place it in the middle of the floor. Only by having the pedal down slightly at all times when the clutch is engaged is the problem remedied. I've become used to this and the problem doesn't surface but this can't possibly be good for gas mileage.
I've also replaced my motor and transmission mounts recently (for other reasons) and the problem didn't change.
Now, as for why the bucking was such a big issue for me even though this site (and others) said it's a common thing with Vipers, my DeLorean started bucking in a very similar fashion the day before the transmission failed catastrophically. Twice. Hence the reason I got rid of the DeLorean.
As for the "37%" theory, total BS. The technician was hoping to get the "glazed-eyes" look from the customer in the hopes he wouldn't be held responsible for not being able to actually fix the problem. Happens all the time. Find a new Viper tech.
Another point, I think we need to define "bucking" as we may be talking about several different things inadvertently. What I'm talking about sounds and acts alot like a large amount of play somewhere in the drive train. The car seems to "bounce" between the drivetrain being "engaged" and "disengaged" about 2-3 times per second. This is accomponied by a clunking sound from, well, everywhere. I've had the transmission, rear-end, half-shafts and other various parts out of my car and have always checked them for play and found nothing out of spec.
Someone else suggested that "the Viper transmission is manufactured with a large amount of play in order to make the transmission last longer when dealing with the large amount of torque and HP the Viper produces". Again, BS. Not only is it wrong, it's completely backwards. A drivetrain with excessive play and large amounts of torque and HP will eat itself quicker than a tight setup. Just ask any transmission specialist or even machinist. Extra play in the dog-legs, shifter forks or gear synchros might make sense but none of these would be felt in the drive-train.
If we're talking about GEN I's, it's probably worth trying new throttle cables assuming you've already tried the adjustment. GEN II's have only 1 cable but there's still an adjustment there. GEN III's with one throttle body...well, that's a whole different animal.
--Rob
