Hi Kevin,
Well surpriise, surprise I have discovered some information that just may help:
As you know the B, 2B, 3B engines were fitted in various models so a direct relationship between the Vin number and the engine number is not possible but by accumulating a sufficient number of B engine numbers they are building a timeline.
The B engine has sleeved pistons so when it is rebuilt new sleeves bring the spec back to factory sizes. These engines were built by Hino (if it has a D on the rocker box then it was built by Daihatsu).
To confirm exacly I could do with the casting number which is situated on the LH side of the motor just to the rear of the injector pump - it will be something like 11xxx-56xxx.
According to the chart above your truck was built at the end of 1983 and the engine number dates from a couple of months before that so that would appear to fit nicely.
Once I have the casting number would you onject if I posted the Vin, casting and engine number into this building database - no other info is posted and it purely to establish the time lines on B series engines which will help when ordering parts.
Regards,
Rodger