You are talking about the coolant blockoff plate circled in red correct?
I can find illustrations of it, but nothing names it or gives a torque spec. I looked in other manuals for cars with a VIN K 3.8 and nothing. I don't know what dealer would not see these engines anymore. We see them all the time. All I can suggest that if the bolts are 6mm x 1.0 thread, apply a bit of loctite or pipe sealer and torque them to 89lbin. and see how it feels with a ratchet. Most 6mm x 1.0's are 89lbin. and I believe these are 6mm x 1.0's. If they are 8mm bolts hand tighten them to what feels good, maybe 15lbft.? I'm speechless. I like to put a number on things and follow torque specs but this is a strange case. Use your sense of feel and best judgement. Don't crack the gasket and tighten them evenly.