Advantage cats

I have a 8.1gi-d volvo moter i bought long block looking for harmonic balancer /bolt/washer part numbers 3861274 3861340 3861264 water pump 3861341 flywheel 3861277 valve covers. this is what im doing maybe some has done this before. any help would b great looking for used parts if possible.
Putting 496 in my 22 foot party cat. all mercuser parts i have "exhaust manifold, sea pump, power stering, oil cooler and pump cooler and dart intake for carb.
Thanks for any help guys