Newbie Question. I just bought a 2007 Chevy Silverado 2500HD, 6.6 LMM, Allison. I'm looking for the best service manuals. I found GM factory manuals online at Helm and eBay, but I believe they only cover LBZ, not LMM (eBay seller confirmed). I know the LBZ and LMM are very similar. Are these manuals good enough, or do I need an LMM supplement? Note: I purchased a Haynes today at Autozone and it doesn't even show a 6.6 at all.