Hi Dachsund!
You should be able to find a shop manual from most of the shop's that sell parts for old vehicles. I have a shop manual--1942-1946--that includes the bigger trucks. You can also get a 'specification' booklet from the Vintage dept at GM. (sorry I haven't got any contact info for the US but I'm sure other's on here will know)
That's a good looking truck you have. Sort of what mine looked like when I first got it.
http://www.geocities.com/jarge46/46_Chev.html Good luck with the project and keep us all updated.
Cheers, George
