If you want the car to last, you'll want to rebuild the engine, if the shop inspects the block and says it is in good shape go with that. Otherwise you are just buying a new engine only to then gut it and replace the components. Unless. You are doing a 4.2L conversion, then you might just want to rebuilf that (from what I have found it's typically cheaper to buy one whole).
Out of curiousity, are you turbocharging it, or supercharging it?
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