Posted by shinyribs on Feb 14, 2013; 5:15am URL: http://vintage-and-classic-hondas.81.s1.nabble.com/Open-header-to-4-into-1-question-tp4036579p4036591.html
I had the same popping issue when i was running just a 4-1 w/no slip on. I did this and it worked out pretty good.