General guidelines for tuning GM vehicles:

Late GTO and CTS-V template Uses .CR3 or .3CL file formats, 3CL used in Predator only. 2004 SOFTWARE E . Most common template for trucks and LS1/6 . Uses .CR3 or .3CL file formats, 3CL to be used in Predator only. 2004 SOFTWARE F . The latest CTS-V template for 2004 models . Uses .CR3 or .3CL file formats, 3CL to be used in Predator only. 2005 ... ................
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