Jim,
You will have no problem as long as you go with a qualtiy sound deadener. For this application I would reccomend dynamat brand, second skin and maybe raamat butyl sound deadening materials.
The good thing with second skin is that you can call and talk to Ant (the owner) he's a cool no BS kinda guy. Rick at Raamat is also a great guy to talk to and will not lead you in the wrong direction.
I almost forgot about Don the creator the sound deadener showdown website. He is a tremendous resource and also has a line of products available.
http://www.sounddeadenershowdown.com/cgi-bin/index.cgi
Avoid edead, brown bread, fatmat as they are not up to this application and typically contain less buty then advertised.
Good Luck and send pics,
KC