Jeep Strokers

Hey, Was hoping to get y'alls opinions on the below. Background. I'm swapping head/camshaft on my new stroker. It has less than 200 miles on it.

First are the pistons. Do these look dirty AF to you? I was pretty surprised to see that much junk on the pistons. I'm hoping it's just the oil residue from installing them? What are your thoughts.
Second is this schmoo i found in the rad filler neck. I wasn't too psyched to see this stuff. New cold case rad, and obv clean block even new upper/lower hoses. On a scale of 1 to F how bad is this? Any thoughts on either are appreciated thanks!

It looks like the block still had a bunch of junk in the coolant passages; not scale or rust, but parts cleaning fluid or oils. As for the pistons, it looks like you are getting oil into the combustion process. It could be PCV/CCV, or just the rings haven't sealed yet. If you had the head done when you did the block, it probably wouldn't be valve guides/seals. If you reused an old head, then the oil could be coming from the top end.

Thanks Mike, I think you're on to something with the pcv/ccv. I Accidentally left it blocked up when i was breaking it in for the first 30ish miles and noticed some smoking early on but have since let it breath (still haven't grabbed a hose to hook it up to the thor intake yet). I also did use the old head briefly. Interesting about the cleaning products you mention... i didn't consider the machine shop used any but hopefully it's flushed what it needed to so far and won't get too much more this time around. Thanks for easing my conscience!