I had really good luck with the factory GM manual for my '77 K5 Blazer. I've used Haynes manuals for my daughter's '00 Honda Accord; my other kids '90 K1500 4X4, '91 C1500 stepside, the '92 K1500 4X4 one of my kids rolled and my '01 2500hd. I don't think the Haynes is as good as the Chilton or factory manuals are but the pictures are pretty good when you need them.
'01 2500hd ext. cab, 8.1 litre gas, 5 sp. Allison auto
3.73 rear end
Mag-Hytec rear diff cover
Amsoil Dual by-pass oil filtration system
Amsoil synthetics all around
265 watt AM Solar, Inc. system