Do the LIM gaskets with the latest design and change the upper plenum and EGR chimney (part of the plenum kit) to repair this. Do not use sealers.
Change the plastic elbows out for aluminum ones but use OE o rings on them. The kit from ATP has been reliable on the ones I have done and have lasted many years without issue. For about $100 and an afternoon its good to go.
ATP plenum
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Factory replacement for the plastic gasket found in the Series II 3800 engine.
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