273 correct heads?

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
Thanks..! Something new to learn all the time. This one had escaped me. I assume standard 318 ports?

Now I wonder of these were used with the lower compression truck 318 pistons that you can find listed.