At 4 pounds cooked, I think they'd be fine left whole, or maybe just split in two. I think the best way (and safest way) to do it is stick the butts in ziploc bags then put them in a cooler full of ice, then cover with ice. With that much pork you'll probably need more than 1 cooler and you'll have to do it in batches. Once the pork is cooled from the ice bath, you can stick in the fridge.
Lang 84 Deluxe
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