Part number 12559357 was 1st design used in 2004 5.3 T code, balanced for fixed pin pistons and the one used in my truck. Mine is basically destroyed. GM in their infinite wisdom discontinued it. My choice is now 12574522. 2nd design, balanced for floating pin pistons. Why the change? I don't have the money to buy new rods to switch over to this new crank. Any thoughts or ideas? Got a new block from Summit. Wanted a new 1st design crank but that's gone out the window. Got a new set of fixed pin pistons before I knew the crank was junk. This isn't going well.

 

Get a used 5.3/5.7/6.0l crank cheap and have it balanced by a machineshop.