Ya, I wish I had bought it now, the guy wasn't asking much, but I had (2) 670's an (1) 617, and a couple 583's sitting around at the time and didn't need another engine sitting around. 1995+ 670 Type Case's have the Black Plate on Top over the Mag, and just (1) Pickup Slot, this one didn't have the Black Plate, and had Dual Pickup Slots, so could be a 92, 93, 94, when the 70mm RV Cranks were available. Since they were dropping the 617 also around 91-92, they probably had a bunch of 76mm Cylinders sitting around. Be interesting to see what Rod they used 125mm or 132mm!Thanks for the info rotaxflyer. I believe you are correct or on the right track at least. All my research is leading me to the same conclusion. I did get a response from LA Sleeve Company but all he said was both sleeves are for the old 640 rotax alpines and they were pretty much the same part just different diameters. I asked if he could dig a little deeper than that because all the 640 alpines were fan cooled and essential the same so it doesn't make sense that there would be two different diameters sleeves for them. I'm not expecting much but we'll see what he has to say.