273, could it be a commando and CAM question?

berlins said
just wondering due to 727 on a 273 -- you ever crawed under the motor and looked at
the engine number stamping above and left of starter under exhaust manifold. Should be some numbers and then a 273, 318, 340, 0r 360. Curious if someone put a bigger motor in there for you - they look pretty much the same from the outside. Would be sweet if you really had a 340!!!

That would have been extremely sweet O:) It's a 273 though, casting is: 2465330 273 LA 1964-66.

Thanks for the tip Cudamark, I also thought about carefully try to feel the top of the piston with a screwdriver through the plug hole. is that a no no?