This is a 4 speed car with manual brakes.

With the piston at TDC, the ridge is barely enough for me to catch with a fingernail. I am not at my dad's so I can't give exact measurement. I'm using Felpro replacement head gaskets to try and keep the compression somewhat down rather than using steel shim gaskets.

Now I know what drone is. I've heard it before just never knew there was a name to it.