Exhaust Riser Gasket?

Fired up my '95 Sport Nautique (351 pro boss 5.8l) yesterday and there was some smoke coming from the rear exhaust manifold riser (I think it's called a riser, where the exhaust manifold connects to the block) on the port side of the engine. I'm going to replace the gasket, but I just wanted to ask a couple of questons.

First, I never took the boat off the trailer and ran it for fear of causing further damage, but when I revved the engine it sounded like it was missing a little. Can the exhaust leak cause the engine to misfire, or should I be worried that water somehow leaked into the cylinders? The oil does not appear milky.

Second, I plan on replacing the gasket myself. Does anybody have any tips or warnings for me? I would hate to cause any further damage to the engine.

Thank you,

bump

its normal for smoke to be in there. Kinda odd that it just started smoking, but I guess the manifolds could loosen from the block.. The exhaust leak from the riser shouldn't cause it to miss at all... I would put the boat in the water and put a load on it. i.e. drive it. Get it up to speed and listen for the miss again.

here's a tip: when you get ready to bolt the manifold back to the block, you can use the outside bolt holes to hold the manifold to the block. Then, you can drop the gasket down in between the block and manifold. So you don't have to line up the manifold, with gasket in place, then thread the bolts on. makes it a bit easier.