Why restrict yourself to pulling the motor out of a school bus? There are probably more trucks out there.
Here's an example. Look at the 1978 International cab & chassis with a DT466 found in the Want Ad Digest, which covers Eastern New York and Western New England, in "Trucks, International":
$1800, and less than 4 hours from Boston, or just a skip and a jump from the Berkshires or Western Connecticut.
If you are further east & north, check out Uncle Henry's, which covers Maine. http://www.unclehenrys.com
A search for "International" in "Trucks - Medium & Heavy Duty" turned up a 1985 cab & chassis with a DT466 in Auburn ME for $1500
A lot of the local Pennysaver-type ad pages have these online counterparts. If there's one local to you, check it out.