If you're getting a timing belt replaced on one of these make sure u do the cams and crank seals while you're at it (and get a timing belt kit that has the water pump in it too), I just bought a 89 LS400 that has about 120,000 on it, timing belt was done at 102,000, but crank n cam seals weren't done, I was already pulling down the front of the motor to fix the timing belt, so I put new seals and 2 new rotor buttons in, cam timing was out about 4 teeth on the righthand camshaft, also the righthand cam sensor wiring has a habit of coming loose and rubbing up against the drive belt (easy fixed with zip tie)...
I've only owned mine for about 2 weeks and I love it, I got it really cheap because it was only running on the left bank due to the right camshaft being out heaps, just got the parts last night and put them in today, runs like a dream now :D