Are the l67 blocks painted black from the factory?

I think all the blocks are, L67 or not.

Cast iron blocks will be painted. Aluminum may be left bare.

Yes.. I had three that were black.

It'* a nice touch before putting it in and should keep it clean for years.

Yes. From the factory GM paints the cast iron blocks, heads, and manifolds black. Most manufacturers paint their blocks. Chevy Orange, Ford Blue, Pontiac Baby Blue, GM Corp Blue (70'*/80'*) etc. GM'* been using black since the late '80s on everything.

It'* not high quality paint. Usually it'* gone by 10 years use...or less.