R60 vs R69S Cylinders

[r60us]

Is the casting of an R69S cylinder the same as an R60 i.e. is there sufficient metal at the top of an R60 cylinder to drill and tap holes for the two extra bolts used to attach an R69S cylinder head. Thanks.

[DarrylRi]

I don't know if there's enough meat there to do that, but the cylinders are definitely distinct castings. R60 (and R67 before it) cylinders have peaked profile fins front and back, while the R50 and R69S cylinders have round profile fins. It's about the only external difference between the R60 and the other models.