hmmm... it does make some sense.. but if this is the case the problem cannot be solved rite as mt car requires a shorter driveshaft.. could you elaborate more on this? btw just curious u sound like a mechanical engineer.. are u? just wondering..
No, im not an engineer. I just have a friend having similar problem b4, his 4AGE 20v is too wide for his AE80 Corolla LE so have to shorten one of the driveshaft as well. After that his car also vibrate like hell. He tried everything, wheel balancing, suspension setup but also din help. Finally we found out its the driveshaft problem coz the driveshaft joint started wearing out. We know its because the shorter driveshaft created a steeper angle between wheel & gearbox. So what he did was shorten the other driveshaft to a similar percentage since both driveshaft r different length. After that the vibration problem is gone. Coz now both driveshaft are balanced again, same proportion as before, so the angle between the gearbox & wheel is similar to original spec. With the driveshaft spinning like how they should be the vibration problem is solved.
But don't just go shorten ur other driveshaft just yet, make sure its really a driveshaft problem 1st. If it is a driveshaft problem look for signs of wear on the modified driveshaft. And make sure you find a good machine shop to shorten the other shaft. This method works for my friend but it might not work for you. So try to consult as many ppl as possible before committing to this method. You've been warned. Good luck!