I just did a lightning motor swap and the pulley system is an 8 rib system and my original 4.6L motor had the 6 rib system. Can I just change the pulley on the front of my A/C compressor or do I have to replace the compressor?

 

Yes Screwed2002, you can purchase an 8 rib pulley and mount it on your a/c compressor from the 2002 4.6L motor, as the a/c compressors for both year models were the exact same part number, the only difference was the amount of ribs on the pulley system. You can buy the pulley from the stealership for about 90 something bucks. It should bolt right onto the compressor. BTW a new a/c compressor with whatever pulley and clutch you need runs about 320 something bucks at the stealership.