Push rod tubes

Took an hour today to start cleaning up the push rod tubes that I removed from each of the cores:

​First step was removing the old dry and cracked o-rings.  GM used simple rubber ones which in the conversion process are replaced with Viton rings.  Viton doesn't dry out with heat and remain supple over the course of the engine's life.  Some were already cracked and missing pieces:

I rummaged around in my tool box and found the perfect thing to use.  Don't ask me if I know how sharp the point is:

Some came off complete, but most came off in brittle little pieces:

Overall in good shape, just tired and grimy.

Next step will be to clean them up. First a bath in Simple Green to get rid of the grime and grease, followed by a polish.  The tubes are made of light steel with a zinc coating.  GM left them bare, but standard practice for conversions is to paint and bake them white with high heat enamel to enhance cooling (or at least reduce heat transfer to the tubes from the cylinders).  I've read online it's best remove the zinc coating and this can be done using an aggressive Scotchbrite pad or bench grinder wheel.