There's one on Ebay right now:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=017&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=270259502328&rd=1

There was also another one recently where this guy was almost finished putting a Cummins in a 1948 Diamond T Truck:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=012&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=220252254835&rd=1

I'm in the very early stages (planning, measuring, tear down, and acquiring parts) of installing a 5.9 Cummins in a 1942 1-1/2 ton dually pickup. It is also using 3500HD/P-30 drivetrain parts. My goal is modern performance, diesel power, and classic looks---and a gooseneck hitch to haul Johnny Poppers (two-cyl. John Deere's).

Bob