Man oh man,, you're doing exactly what I intend to do to my 1950 1.5 ton!! I'll have more work to do trying to fit that honking engine between the fenders though.
I'm also planning on using a Dana 60 front, but I'm retaining the 6.17 gear ratio and adding the same to the Dana front. I've got a Brown Lipe Aux tranny to step it back up for highway cruising,,,, that and an S6-650 6-speed or an NV-4500 5 speed OD should make it highway friendly. I'm still debating whether to use the NP271 transfer case that comes behind the S6-650, or a divorced NP205, and put it behind the brownie. That way I could have the brownie in OD while it's in 4x4. That would make for a pretty long front driveshaft, but it would keep the u-joint angles down and permit me to eliminate the driveshaft carrier and go to a single piece rear driveshaft.
I haven't looked into it in much detail, but I'm thinking I'll use a more modern steering box, and possible move it outboard of the frame, using u-joints to shift the steering column over as it exits the firewall.
Anyway, it sounds like a GREAT project! Hopefully we can trade some stories and help eachother out. I know a lot of people say the duramax swap has too much electronics work involved and some even say it's impossible... Naysayers,, it's just more work. If you haven't looked into the electronics work involved, there's a guy on eBay that has done such a swap into a 70's Chevy and has a CD of all the information it took him to wire everything up correctly and retain stock or Autometer gages. Here's the link:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=200209212849&ssPageName=MERC_VIC_ReBay_Pr4_PcY_BID_IT&refitem=200198331089&itemcount=4&refwidgetloc=closed_view_item&usedrule1=CategoryProximity&refwidgettype=cross_promot_widget&_trksid=p284.m183&_trkparms=its%3DS%252BI
