It looks like our 2005 GTO takes a PF46 filter. The local tells me that this is the only filter recomended for the LS2. The local speed shop suggests using the PF59, which they say is the same filter with the same featues only longer with more capacity and filtering ability. Does anyone have any thoughts on this. Does the larger filter provide more capacity and filtering and help cool the oil a little? Or... if we are changing oil every 3,000 is the PF46 really all you ever need. Not a big deal, just wondering. Thanks.