Hi; I have a 2002 GMC YUKON with the 6.0L gas engine. Some of you know about all the noise these engines make; piston slap, valve train, etc. Anyway the owners manual spec. 5W-30 and I was wondering about the Amsoil series 3000 HDD 5W-30 oil. If anyone knows the Zinc & Phos. PPM please share. Also is this likely to cause cat. converter poison? Thanks for any input.