I would concentrate on the basics first, tuning ect, then converter, then heads. I don't think the head is big enough for the cubes, but I bet some sharp tuning will make quite a bit of difference
The camshaft isn't the problem. There isn't a non-offset rocker head that will support a 4" stroker to spin much higher than 5500-5800. You can cam it, header it, single plane it, carb it, till the cows come home, won't help. Part of my mild disdain for strokers is exactly this. J.Rob
