mornin. my buddy has a 2005 tc-55 with only 1,000 hours on it and blew a head gasket yesterday. i have a 2007 t-2420 which is the same thing just a different number.he was told from the dealer that it was common for them to go at about 500 hours. i was woundering if anybody knows if this problem was taken care of befor my t series came out. i really don't want to have to worry about this every time i use it. thanks.