I have a brand new Chevrolet Silverado with a 5.3 V-8 , I like to keep it all A/C Delco , here is what I found out , the PF63E is the environmental type oil filter with the "Ë"core , OK what is the PF63F? and a regular 63? thanks , I heard and by reading on here to stay away from the PF63E , thanks in advance for you answers.