I have a 383 that has about 800 miles on it. This is my first build up and engine swap so I had a few hic-cups along the way. I finally have it running about where I want it to but I keep getting oil around the #7 plug. Enough that is leaves a draining stain around the plug and splashes off the flywheel. It had done this in the beginning so on a mechanics suggestion (because it was a new build and had stop and go traffic miles on it), I took it out on a 90 mile trip to see if the open road would help clear things up. It seem to work. Now its about a month later and it's worse than before. I have Dart angle plug heads running Royal Purple oil. I know I'm getting a little blow-by because it's hard to tighten these plugs all the way down with headers on an angle. Just to make sure 12 degrees initial/32 degrees overall, 10:1