Today I changed the oil in the 2000 WS6 I bought not long ago..I bought a Fram PH3065 and it would not fit....so I changed it for AC Delco PF46 and it would not fit either...So I pulled the old filter out of the oil dump and it was AC Delco PF48E..I thought those fit on later model LS1? All the books called for PF46...

 

A PF48 would have the larger Gen IV thread size... however, all this really tells you is that you have a Gen IV oil pan (since the filter threads to the pan and not the block).

 

Its def a Gen IV pan...Im going to try to get the casting # off the block tomorrow

 

The LS2/3 oil pans fit into our 4th gen f bodies??

 

Mine def has the larger thread size, as the PF48E will fit, and the PF46 will now