Nah actually... they had casting 920 heads 1967... then they also had a closed chamber 318 truck head with a water heated cross over which you could block and run on any la motor casting 234 heads..being a water cross over..that means blind exhaust ports instead of one on each head having a hole in the bowl.
You can buy a set here..
68-74 Chrysler 5.2L 318ci V8 - Truck - 234 Cylinder Head