Power is back and it is boosting and driving fine. Still ticking ofcourse. So I'm trying to think what would cause it to "slip" and after letting it sit for ~1hour it would be fine. I wouldn't think it is the clutch. Possibly a leak in the headgasket? Or maybe a small leak between the upper and lower intake manifold? Which I just put back on last week. But I've put over 100miles on it since then.