Small block with over 500 passes, 12 to 1 414 W5- 325/240 cfm @.650, small solid roller 260/264 @.050 .685 lift 106cl on 106, max ported M1 small port, 2" spacer, race demon 1000, square jet 90s no pvs, short header 30" 1 3/4 to 1 7/8, 3.5 collector, we turn it to 7k, Intake runners has been very clean till now, starting to see signs of darkening in runners to carb base plate.... whats up with this????