I have one driver side head for sale. It is the 3927186 head. This means it has the 2.02/1.60 valves and 64cc chambers. It has accessory mounting threaded holes front and rear. All threads are clean. Date code is Aug 22, 1968 which puts it in the 1969 model year. Email me your zip code for UPS freight quote.
Surely someone has the other brother from a different mother that matches this and is dying to reunite them.
The Jalopy Journal
