A friend has a 96 Buick GS Regal with the 3800 Series II(Non Supercharger)
He called me up and had me stop by to look at his car; it was knocking like the world was going to end!!!
Long story short, the harmonic balancer was bad, and the car knocked and ran awful!!
Remove-Replace, all is well.
Sorry to hear about your car. If you get lucky, you can find a junkyard engine.
Some junkyards even can do the install for extra $$$
Remember at least you know your Bonnie'* history. Replacement may be better than looking at an "unknown" beater, which may blow up 300 feet down the road.