Found! 6-19-68 340 engine block.

HemiSSDart said

Aftermarket paint manufacturers vary wildly in color. I too have seen many original paint 340's and 383/440's painted in turquoise, those colors vary also depending on how long and hot they have been run and how much grease has penetrated the paint. We will just agree to disagree at this point, I have studied this issue for decades and we all have our opinions and will never know the truth.

Click to expand...

Fair enough, agree to disagree. For sure over time paint colors changes. I know my friend viewed multiple comparisons back in 69 with brand new cars so he will take it to his grave. LOL. Personally I think there may have been a TSB? Even though I haven't seen one? But the tint was altered slightly (for whatever reason) on the 340. As we both know back in that day there was not a lot of automation & changes came from the hip quickly. Enjoy your Mopar ride(s) and thanks for your thoughts & knowledge. I hope someone finds this block to match a car!