Hey there,
The "L" engine is a naturally aspirated diesel motor. The predecessor to the 2L, 2LT, and 3L, which is in my 1990 HiAce. Heres a Toyota factory repair manual for the "L" engine on eBay:
http://www.ebay.com/itm/Toyota-Picku...lXr6y2&vxp=mtr
For determining specs on JDM imports, I use toyodiy.com. You can plug in the vin number, and it will allow you to access a database of part numbers that will be useful for you along you journey.
On another note, a friend of mine who's owned a Toyota repair shop in Portland since 1972 (Willamette Boulevard Service Center) just unearthed a set of photos he took in yellowstone in 1981. They're of a HiAce. It was the first Toyota van he'd seen in the states, it had traveled up from Costa Rica. Very cool looking rig.
Good luck with the HiAce!
-Danny-