Engine runs fine but seems to seize after wot

If your valve lash is too tight an engine will start and run seemingly OK until the valves start to come up to operating temp and then then they tend to be open a tiny bit when they should be closed tight, the engine just slows down and dies. Will not restart until it cools down. I would try opening the lash up about .020 and try again. And yes it can happen with a hydraulic as well as solid cam. Good luck