Something I see in the picture of your engine that nobody has mentioned yet would be the aftermarket pulleys. I just went through this with the 512 in my Challenger. I changed the radiator to a different one with the aluminum shroud with 2 fans in it but, the one thing I think is going to help...
No, I do not. I thought I had saved what it went for at Mecum but, I can't seem to find it. If I find it I will let ya know. The car was in Mopar collectors guide a few years back when the local guy owned it.
This car was local to me for a long time. He sold it to Tim Welbourn a few years back but, I see Tim sold it at Mecum a couple years ago. This picture was taken at Mcacn in Chicago right after Tim bought it.
No where in the ad does it say this car is original or unrestored. It also doesn't say the 86 miles is the original miles. Unless I missed something...
Could also be a contaminant like silicon on the surface. Products like Armor All are full of silicon. Also some wax and grease removers will cause this if not dried off while wiping the car down, if you allow it to dry on the surface it can cause a reaction similar to this.