Interesting 302 Block Marking

[dannystarr]

Anyone else see or have this marked on a Z/28 Block. Or ANY block. Never seen this before. This took a while to try and get it photographed well. I have to try to duplicate it now that the block has been cleaned and rebuilt. There is JUST enough residual left to copy. Do I put it under the paint hoping it bleeds through, or lightly OVER the finished paint? What product do I use and where do I get it?
Either way, very cool marking that I assume was done at the Flint Plant? ... Danny   

[dannystarr]

couple more

[rszmjt]

Hi Danny, I have a 6,000 mile 70 Camaro  LTI that has the block pad code CTB and it is marked on the side of block too, pretty sure it was a grease type pencil application, either done at Flint of the Norwood plants to identify engines in the rack easily. Heres a link with pictures of it from years ago. I have also seen it on survivor cars 69 DZ etc.

http://chevynova.org/1970LT1_Engine.html

Mike.

[BillOhio]

My DZ looked like it had OK on the drivers side of the block there.  In one book I had it showed blocks before paint with codes wrote on the side.  I cant think which book it was. Maybe how to hot rod your small block chevy

[firstgenaddict]

One of my 69 engines had 302 on the side...
My LT1 Corvette has CGZ which is the suffix code.
The 70 Z28 I had with 30k miles also had the suffix code on the side in yellow grease stick.

[169INDY]

Product:
https://www.uline.com/Product/Detail/S-19600Y/Paint-Markers/Markal-B-Paintstik-Markers-Yellow?pricode=WB3469&utm_source=Bing&utm_medium=pla&utm_term=S-19600Y&utm_campaign=Markers%2B%2F%2BStencils&utm_source=Bing&utm_medium=pla&utm_term=S-19600Y&utm_campaign=Markers%2B%2F%2BStencils&gclid=1d7c69d578f21d318efd08239c54b51d&gclsrc=3p.ds&msclkid=1d7c69d578f21d318efd08239c54b51d

[bertfam]

I remember John stating several years ago that most, if not all blocks were marked with the yellow or white crayon (wax pencil) upside down so they guys building the engines wouldn't accidentally install the wrong pistons, cam, etc... in the block. He said Chevrolet had been doing this almost forever!

Ed

[maroman]

I agree, seen it before.  My '67 Corvette had the code written in grease pencil after it was hot talked.

[KurtS]

Agree, common. And it was under the paint.

[Kelley W King]

How does grease pencil or crayon stay there after hot tanking or other paint removal?

[bertfam]

I don't think what you're seeing is the actual marker, be it crayon or grease pencil. It's the "shadow" if you will of what's left after 55 years of being hidden under paint.

Ed

[Kelley W King]

I think you are right Ed, maybe the marking kept the paint chemicals from soaking in the metal discoloring it and later we see two shades of bare metal.

[bertfam]

I think you are right Ed, maybe the marking kept the paint chemicals from soaking in the metal discoloring it and later we see two shades of bare metal.

Yes, that's exactly what I was trying to say! Thanks for putting it in better words!!

Ed

[jaybee]

I had a MO block several years ago that had that 'tell' on the sides.

[Rossterman]

My 70 z28 had the ctb written in crayon on the block side.