That's the exhaust manifold cover and baffle plate. As Chris said, it's a real pain to work on, especially if those 5/16" stainless bolts have seized in the aluminum block. You have to use a combination of shock on the bolt head, and heat to remove. And if they don't want to move with just normal force on a wrench, they're stuck.
Sometimes stuck so bad that you have to drill the bolt head off, then once you've gotten all the bolts out and covers removed, grab hold of the bolt stub, heat the heck out of it, and hope it breaks loose. At least with the covers removed, you can apply heat to both sides of the block where the bolt threads into.
Now, back to your external leak, as long as you're not getting water in the cylinders (gaskets leaking/spraying internally), you could attempt a stop-gap repair by attempting to seal with RTV. Don't use Ultra Copper; black or Hi-temp red work well. Make sure the area is clean & degreased so the stuff will stick.
One other thing you might try, it to very carefully lay a wrench upon the couple of bolts nearest the leak, and see if they will move (in the tighten-direction only!).
If the bolts will move, snug them down. Just don't force them, as you don't want to break off a stainless bolt in an aluminum block. That is, unless you like doing Heli-Coil repairs! It's just about impossible to drill out a stainless bolt busted-off in aluminum, and just tap out the hole. The left-over shards of stainless foul the tap, sometimes breaking it off in the hole or shredding the alum. threads. Making it worse than when you started!
Give the tightening thing a shot and if that doesn't work, just seal 'er up with RTV until you're ready (if ever!) to take the Big Plunge (pulling powerhead for good access to the cover/plate and replacing gaskets).
HTH..........ed
