069 is correct until about Jan of 1968, then the 163 was phased in. There are two different 069s so make sure if you're searching for one it has the plenum dividor and not three holes, that's the earlier version.
Also, be very careful on the 069s, the runner bolt hole areas tend to crack here a lot. Many of these that we get in for reskinning have to be fixed. So if you buy one, inspect it carefully.
Jerry
Jerry