Engine swap, 2000 3.8 into a 97 LeSabre

[woods_man]

Darn, my 97 LeSabre engine died at 172K miles. I have had better luck in the past, with 3800 engines, but didn't buy this car new. I am intending to put another 3800 engine from a 2000 LeSabre into the car. I'm told that I will need to change the oil pan and harmonic balancer-use the ones off the 97. The oil pan makes sense, but I'm trying to understand whether swapping the harmonic balancer is really the right thing to do. Isn't the harmonic balancer specific to the engine? So if it is changed it will not be in balance?
Or is there something in the computer that has different timing on the 97 compared to the 2000? Anybody know for sure?

[buickmastermind]

they are swappable
if the VIN shows the same engine code ("c")