5th red truck

Hi Guys, new to this forum so be gentle, I have a 2009 siverado 1500 crew cab, 5.3 6 speed auto. Have had it since dec2009 put about 60,000 miles per year pulling jet ski trailers. for work. It now has 209k and is on its second transmission and needs another camshaft and lifters. gm helped me on the first camshaft and i did not ask them for aid on the transmission. they have declined to help me on the second camshaft . Am i just being a cry baby or should i just gladly hand them 6.5 grand for a new motor. my last 5.3 without AFM went 290k on the same engine and transmission. I have always used synthetic oils. Maybe the problem ?