- Location
- Knoxville, TN
the grey head and cyl are a later model setup and have a better port timing than the black set.
does it have a pair of threaded bosses on the front of the cyl?
even though you know now, it says 650 or 750 right on the case. Near the intake manifold I think, but it could be on the other side. Either way, it's stamped into the case.