I have a small I/O with a mostly stock 350 SBC (out of an 84 Suburban). When I put it in the boat I changed the cam to a Comp 268H (advertised duration 268in and ex, @.050 218 in and ex) with a .454 lift. I put this cam in years ago, without changing springs or rockers. I have kept the RPM at or below 4K for fear of floating the valves with the stock springs. I am planning (at long last) to put in the recommended springs this year, and while at it I was wondering if it actually needed long slot rockers? The stock rockers have not been an issue - that I am aware of - but thought I would ask the question.