3gm is an earlier version of the 3gm30. I believe that Yanmar bored
out the 2Gm and 3GM to create more power. There may have been other
changes. I think the 3gm 30's were introduced in 1986

On Thu, 12 Aug 2004 16:50:20 -0400, "Ron" wrote:

Can anyone tell me the difference between these two diesel engines?