started up the wifes 340 puma, and noticed it was a liitle louder than usual. checked the 4 nuts that bolt the manifold to the engine and found that they needed snugged up. also found that one of the gaskets was blown. is this a normal thing ?

yep, with age they get brittle and if the bolts come loose they blow out. as far as why the bolts came loose i guess maby engine vibration or heating and cooling over time streched the stud's .

after you replace the gaskets i would check the compression in the cylinders. *just to make sure that it didn't suck in some air & melt down one of your pistons!! *i've seen them still run with melted piston, but if you catch it right away then you won't have to worry about cylinder scoring!!