Casting of the L36 LIM did not change from 90'* to 00'*, so yes, you will find your stock LIM outlets are as crappy as you've seen in the threads you saw.
Make sure your JY LIM has flat, non-warped/non-gouged mating surfaces (bring a straight edge), doesn't have mangled injector holes, doesn't have any stripped threaded holes (bring an M8-1.25 bolt), and isn't too severely coolant-pitted on the flanges. I wouldn't pay more than $50 shipped for an excellent L36 LIM, $30 to $40 at a u-pick.
2004 Buick Lesabre Limited, Gran Touring; Bone Stock
1998 Buick Lesabre Limited, Gran Touring; Mods: Poly sway bushings/endlinks, Tru-Cool trans cooler, Thrasher shift kit (med), PLIM, front PEM; Mods in progress: Alot of stuff, but slowly...