I am working on a 1980 kz650 engine with a cracked head. The head I have that I will overhaul is a '78. The only difference is that the pre 1980 heads on the 650 and 750 don't have the air ports near the exhaust vales, and the valve cover dosent have the air valves.
My question is this: Was this adaptaion important? Is the 1980 and after design superior? Is there a significant difference such that I should find a head '80 and after. I got a good '78 head, clean with fantastic valve guides. I am going to have valves ground and lapped and new springs and seals put in.
If I knew what I was doing all the time life wouldn't be any fun.
'80 KZ650 E 700cc, dyna ignition and coils, frame up restoration, daily driver
'81 KZ1300 A3 full restoration, custom big bore pistons, 1400cc 6 cylinder super bike
"77 KZ650 B1 - Barn Find, work in progeress
"74 Yamaha DT 400 Enduro
