Rattle can don't match anyway these days.
I tried to spray my /6 a few months ago with por 15 engine paint and I don't know if it was because I had an old pint of their engine paint or if that's just how it is but the spray came out and laid on almost transparent. After 3 coats the freeze plugs were still silver. I'd had that paint here for 5-6 years though it was on a shelf in a closet in the house so I know it never froze. As much as I like the other por paint products and as well as they have treated me in the past I can't recommend their engine paint.
Next time I will buy a fresh can, and I will try either bill Hirsch engine paint or the KBS stuff. I have used the KBS hi temp manifold paint on this same slant 6 build, and I really like how that turned out.
I went to the paint shop looking for por version but they were out.
I've used kbs chassis paint as well as por 15 version and can't really tell any difference. So we'll see.
On that /6 that I sprayed mopar blue, what paint did get on there looks to be stuck but good, if it weren't for the poor coverage I'd have been happy.
I ended up spraying over the por 15 with duplicolor rattle can. Just to get it done as I was painting it on a Sunday.
