No, they aren't. Some '186' heads were ground/prepared for 1.94" Intake valves.. In fact, in searching for these old heads these days, one might even PREFER to find the 1.94" valve versions for prepping for 2.02 usage... It allows cutting away from metal to get to fresh metal and maybe eliminate some cracking of the seats. And Yes, the combustion chamber will need some work to match the 2.02 factory shape...