The early busses (50 to 67, T-1) were like type I (1200, 1500 and 1600 cc) and the mid ones (68 to 79, T-2) were type IV (1700, 1800 and 2000cc) and later (79 on, T-3 )they went to diesel and water cooled after that. There are posts here and on the other 914 site at
http://www.dgi.net/914/ and they spell out the differences.
[This message has been edited by john rogers (edited 04-18-2000).]