VIN Decode for 1969 GMC 8500

[lgvl]

So, i'm looking at a 1969 GMC 8500 but there is no information about the engine or transmission. There is, however, a VIN. But i'm currently at work on a vessel at sea and our internet drags like snail's tits and I can't find a VIN decoder that will work. Can someone give me a hand and help me decode this thing? It would be much appreciated. Keeping my fingers crossed it's a Detroit Diesel but i'm betting it's a 366ci. Thanks! -Ryan

HM80A-D106237