Triumph 650 barrel stud hollow dowels ???

Well, I'm "about" halfway thru a 1969 triumph 650 engine rebuild. Looks like the drive side case half has space for two "p/n 70-8751 hollow dowel" on the two inner cylinder base studs. :shock: As far as I can tell by the parts books I have, earlier 650s list two, but the 1971 and later 650s only list only one. Why would this be ??? So ... is it acceptable to just use one; or should I use two ??? I suppose two will more positively locate the cylinder barrel to the cases, but may also make it more difficult to fully seat the cylinder barrel. Perhaps Triumph went to using only hollow dowel on later 650s ... for this reason ???

Or ... maybe the later parts books are misprints, and there should always be two ??? BTW, the barrel is from a 1971, and the drive side inner stud two holes are larger diameter than the rest.

If there's counterboring in the case and barrel for two dowels, use two.